Positive active material
The application is filing date JIUYUE in 2010 9 days, Application No. 201410014566.X, invention entitled " positive pole is lived
Property material " divisional application, and the application of Application No. 201410014566.X is filing date JIUYUE in 2010 9 days, application number
Be 201010279232.7, invention entitled " positive active material and preparation method thereof, positive pole and nonaqueous electrolyte battery "
The divisional application of application for a patent for invention.
Technical field
The present invention relates to a kind of positive active material, positive pole, nonaqueous electrolyte battery and prepare positive active material
Method.More particularly it relates to an be capable of having by it when charging and discharging in hot environment
High-performance and present the positive active material of nonaqueous electrolyte battery of very low capacity deterioration, positive pole, nonaqueous electrolyte battery with
And the method preparing positive active material.In particular it relates to a kind of positive pole including lithium-compound transition metal oxide
Active substance.
Background technology
In recent years, with portable set, popularizing, to small-sized Gao Rong of such as video camera and notebook personal computer
The demand of amount secondary cell and battery increases the most day by day.Currently used secondary cell include use alkaline electrolyte nickel-
Cadmium cell and nickel-hydrogen cell.But, the shortcoming of these secondary cells is cell voltage the most about 1.2V and is difficult to improve energy
Metric density.Therefore, nowadays the lithium rechargeable battery that voltage is higher higher than other battery system and energy density has obtained extensively
General utilization.
But, owing to having higher charging voltage, therefore, asking of lithium rechargeable battery compared with other battery system
Topic is, when using in the way of keeping the long period in the charge state, and the longevity that its capacity can be deteriorated and it is useful
Life can be shortened.During additionally, use lithium rechargeable battery under in high ambient conditions, the rising of internal resistance can be produced,
It is made to be very difficult to guarantee enough capacity.Strongly need to solve the scheme of these problems.
LiCoO2、LiNiO2It is widely used as lithium rechargeable battery with other lithium-compound transition metal oxide granule
Positive active material.Recently, it has been proposed that by forming coat at the surface of the particles or making some materials from particle surface
Diffusion improves the state of particle surface to obtain the various technology of the more preferable performance of lithium-compound transition metal oxide granule.
Such as, in Japanese Patent No. 3197763 (hereinafter, referred to as patent documentation 1), it is shown that slaine or hydrogen
Oxide joins the method in positive pole.(hereinafter, the referred to as patent literary composition additionally, Japanese Patent Publication Hei 5-47383
Offer 2) show one phosphorus (P) cobalt-coating acid lithium (LiCoO2) the technology on surface.Japanese Patent No. 3172388 is (under
Wen Zhong, referred to as patent documentation 3) and Japanese Patent No. 3691279 (hereinafter, referred to as patent documentation 4) show a kind of use
The method on the surface of metal oxide-coated positive active material or positive pole.
Japanese Patent Publication Hei 7-235292 (hereinafter, referred to as patent documentation 5), Japanese Patent Publication
No. 2000-149950 (hereinafter, referred to as patent documentation 6), Japanese Patent Publication the 2000-156227th (hereinafter, claim
Make patent documentation 7), Japanese Patent Publication the 2000-164214th (hereinafter, referred to as patent documentation 8), Japanese Patent Publication
No. 2000-195517 (hereinafter, referred to as patent documentation 9), Japanese Patent Publication the 2001-196063rd are (hereinafter,
Be referred to as patent documentation 10), Japanese Patent Publication the 2002-231227th (hereinafter, referred to as patent documentation 11) etc. shows
Wherein be evenly coated with lithium-compound transition metal oxide the surface of granule method and wherein composite oxides from granule
The method of diffusion into the surface.(hereinafter, referred to as patent documentation 12) is shown additionally, Japanese Patent Publication the 2001-256979th
Go out the positive active material that the block of wherein metal-oxide is deposited on metal oxide layer.Japanese Patent Publication 2002-
No. 164053 (hereinafter, referred to as patent documentation 13) are shown in which to be formed on the surface of the core comprising lithium compound to comprise
The positive active material of at least one surface-treated layer of at least two coating element.
Japanese Patent Publication the 3157413rd (hereinafter, referred to as patent documentation 14) discloses one wherein at granule
Surface on the positive active material of coating including metal fluoride is set, and Japanese Patent Publication the 3141858th (
Hereinafter referred to as patent documentation 15) show a kind of coating including crystal metal fluoride.Additionally, Japanese Patent Publication
No. 2003-221235 describes and specifies fluorine XPS (x-ray photoelectron power spectrum) energy on the surface of granule.When this
The inventor of invention prepares positive pole according to the disclosure by the method for mixed metal fluoride thermally treated mixture and lives
During property material, it was observed that about the actual effect of high temperature dwell sustainability, but this effect be limited to the surface to granule effect and
It is insufficient based on actually used performance.And, U.S. Patent No. 7,364, No. 793 (hereinafter, referred to as patent documentations
16) disclose and a kind of for lithium, there is high-affinity and the compound of cation and lithium-transition can be supplied by wherein making
The method of composite oxide of metal reaction and the material that obtains.
Summary of the invention
But, according to such as in the method for patent documentation 1, slaine or hydroxide are joined have common uniformly
In the lithium-transition metal oxide of form, the resistance of electrode increases and is difficult to obtain enough capacity.At patent documentation 2
In method, the capacity caused due to coating reduces the biggest so that positive active material can not make us for actual should being used to say that
Satisfied.If merely with the coating element, painting method and the coated form that disclose in document 3 and 4, then patent documentation 3 and 4
Method as being all unsafty for improving the technology of battery performance under the high temperature conditions.Moreover, it has been found that,
Increase coated weight to obtain abundant effect can cause hindering the diffusion of lithium ion so that it is very difficult in practical application area
In charge-discharge current value under obtain enough capacity.Therefore, the method is the discovery that unsafty.
Find that the method disclosed in patent documentation 4 to 9 is for improving cycle characteristics to the highest degree and suppressing high
Resistance during temperature use is unsafty for improving, although can keep high power capacity by the method.When logical
When crossing the method and structure disclosed in patent documentation 12 to prepare positive active material, it is difficult to obtain enough recharge-discharge effects
Rate, and capacity is largely lowered.In the method for patent documentation 13, if individually using surface to process, then due to
The effect that the method produces is limited.Additionally, when prepared by the method disclosed during positive active material is actual by the document, shape
Become homogeneous multiple layer, when the most at high temperature using, do not find the effect preventing resistance from raising.
About the metal fluoride that the method according to patent documentation 15, simple electronic conductivity and lithium-ion-conducting are low
Coating causes recharge-discharge performance to significantly reduce, and it is insufficient to the effect of the charge-discharge characteristics under hot environment
's.When the method disclosed during the present inventor is by patent documentation 16 prepares positive active material, occur as being coated with
Cover the discontinuity of material of material addition or come off, and producing inactive compound such as oxide and lithium fluoride so that being coated with
Cover function can not fully be presented.Additionally, it is difficult to obtain the recharge-discharge performance of actually used level, because charging-putting
During electricity, the migration of lithium ion is interrupted at solid liquid interface.Additionally, it was additionally observed that the trend that capacity reduces, because from lithium-transition
Composite oxide of metal loses lithium.Therefore, it is unsafty according to the material of the document.
Accordingly, it would be desirable to, charge-discharge cycles excellent high to capacity and present the least when being used for hot environment
The positive active material of deterioration, the positive pole using such positive active material and rechargeable nonaqueous electrolytic battery and preparation
The method of such positive active material.
According to the embodiment of the present invention, it is provided that a kind of positive active material prepared by following steps: lithium will be contained
Compound, containing the compound of transition metal being included in solid solution and containing the metallic element being different from transition metal
The compound mixing of M2, and burn till mixture to form composite oxide particle;On the surface of this composite oxide particle
Deposition comprises the compound of at least one element in sulfur (S), phosphorus (P) and fluorine (F);And burn till deposition on it and have and comprise
The composite oxide particle of the compound of at least one element in sulfur (S), phosphorus (P) and fluorine (F);The most each composite oxygen
Chalcogenide particles has such Concentraton gradient: the concentration of metallic element M2 increases from the center of composite oxide particle to surface,
And make at least one element in sulfur (S), phosphorus (P) and fluorine (F) to assemble (aggregate, cohesion) at combined oxidation
Presented on the surface of composition granule.
According to another embodiment of the present invention, it is provided that a kind of positive active material including being prepared by following steps
Positive pole: by lithium-containing compound, containing the compound of transition metal being included in solid solution and containing being different from transition gold
The compound mixing of the metallic element M2 belonged to, and burn till mixture to form composite oxide particle;At these composite oxides
On the surface of granule, deposition comprises the compound of at least one element in sulfur (S), phosphorus (P) and fluorine (F);And burn till it
Upper deposition has the composite oxide particle of the compound of at least one element comprised in sulfur (S), phosphorus (P) and fluorine (F);By
This each composite oxide particle has such Concentraton gradient: the concentration of metallic element M2 is from the center of composite oxide particle
Increase to surface, and make at least one element in sulfur (S), phosphorus (P) and fluorine (F) to be gathered in composite oxide particle
Surface on presented in.
Other according to the present invention embodiment there is provided a kind of non-aqueous solution electrolysis including positive pole, negative pole and electrolyte
Electrolyte cell, wherein positive pole includes the positive active material prepared by following steps: mix lithium-containing compound, containing being included in
The compound of the transition metal in solid solution and the compound containing the metallic element M2 being different from transition metal, and burn till
Mixture is to form composite oxide particle;The surface of this composite oxide particle deposits and comprises selected from sulfur (S), phosphorus (P)
Compound with at least one element in fluorine (F);And burn till deposition on it and have and comprise selected from sulfur (S), phosphorus (P) and fluorine (F)
In the composite oxide particle of compound of at least one element;The most each composite oxide particle has such concentration
Gradient: the concentration of metallic element M2 from the center of composite oxide particle to surface increase, and make selected from sulfur (S), phosphorus (P) and
Presented at least one element in fluorine (F) is on the surface being gathered in composite oxide particle.
Comprising selected from sulfur (S), phosphorus (P) and fluorine of the positive pole of the present invention and the positive active material of nonaqueous electrolyte battery
(F) pyrolysis (i.e. thermal decomposition) product of the compound of at least one element in or this compound of positive active material is preferred
There is the fusing point of more than 70 DEG C less than 600 DEG C, and also preferably there is the average diameter of below 30 μm.
Embodiment there is provided a kind of method preparing positive active material according to another, comprise the following steps: mixing contains
Lithium compound, containing the compound of transition metal being included in solid solution and containing the metal unit being different from transition metal
The compound of element M2, and burn till mixture to form composite oxide particle;The surface of this composite oxide particle sinks
The compound of long-pending at least one element comprised in sulfur (S), phosphorus (P) and fluorine (F);And burn till deposition on it and have and comprise choosing
The composite oxide particle of the compound of at least one element in bin cure (S), phosphorus (P) and fluorine (F);The most each combined oxidation
Composition granule has such Concentraton gradient: the concentration of metallic element M2 increases from the center of composite oxide particle to surface, and
And make at least one element in sulfur (S), phosphorus (P) and fluorine (F) with the shape being gathered on the surface of composite oxide particle
Formula exists.
Be deposited on the surface of composite oxide particle comprise in sulfur (S), phosphorus (P) and fluorine (F) at least one
The compound of element is melted to be uniformly present on the surface of composite oxide particle after being preferably melted or thermally decomposing.Also
Preferably on the surface of composite oxide particle, remove be deposited on the surface of composite oxide particle comprise selected from sulfur (S),
The cation of the compound of at least one element in phosphorus (P) and fluorine (F), and make the anion of compound be included in compound
Element reaction in oxide particle.
Additionally, according to another embodiment of the present invention, it is provided that one includes lithium-compound transition metal oxide granule
Positive active material, this lithium-compound transition metal oxide granule comprises lithium, primary transition metal M1 and is different from mainly mistake
Crossing the metallic element M2 of metal M1, metallic element M2 has from the center of each granule to the concentration ladder of the metallic element M2 on surface
Degree, wherein meets in the range of 0.020≤d≤0.050 at ratio d (%) from surface to certain depth, and molar fraction r (%) is full
Foot formula 0.20≤r≤0.80, wherein ratio d (%)=[(quality of primary transition metal M1)+(matter of metallic element M2
Amount)]/(quality that granule is overall), and wherein molar fraction r=(the material amount of metallic element M2)/[(primary transition metal
The material amount of M1)+(the material amount of metallic element M2)], wherein, described primary transition metal M1 be selected from nickel (Ni), cobalt (Co),
At least one in manganese (Mn) and ferrum (Fe), and wherein, described metallic element M2 is selected from manganese (Mn), magnesium (Mg), aluminum
(Al), at least one element in nickel (Ni), boron (B), titanium (Ti), cobalt (Co) and ferrum (Fe).
According to another embodiment of the invention, it is provided that a kind of positive pole, this positive pole includes that comprising lithium-transition metal is combined
The positive active material of oxide particle, this lithium-compound transition metal oxide granule comprises lithium, primary transition metal M1 and not
Being same as the metallic element M2 of primary transition metal M1, metallic element M2 has from the center of each granule to the metallic element on surface
The Concentraton gradient of M2, wherein meets in the range of 0.020≤d≤0.050 at the ratio d (%) from surface to certain depth, rubs
You mark r (%) meets formula 0.20≤r≤0.80, wherein ratio d (%)=[(quality of primary transition metal M1)+(metal
The quality of element M 2)]/(quality that granule is overall), and wherein molar fraction r=(the material amount of metallic element M2)/[(master
Want the material amount of transition metal M 1)+(the material amount of metallic element M2)].
According to another embodiment of the invention, it is provided that a kind of nonaqueous electrolyte including positive pole, negative pole and electrolyte
Battery, positive pole includes the positive active material comprising lithium-compound transition metal oxide granule, this lithium-transition metal composite oxygen
Chalcogenide particles comprises lithium, primary transition metal M1 and is different from the metallic element M2 of primary transition metal M1, and metallic element M2 has
There is the Concentraton gradient to the metallic element M2 on surface from the center of each granule, wherein at the ratio d from surface to certain depth
(%) meeting in the range of 0.020≤d≤0.050, molar fraction r (%) meets formula 0.20≤r≤0.80, wherein ratio d
(%)=[(quality of primary transition metal M1)+(quality of metallic element M2)]/(quality that granule is overall), and wherein rub
That mark r=(the material amount of metallic element M2)/[(the material amount of primary transition metal M1)+(material of metallic element M2
Amount)].
According to the present invention, by meeting the scope of 0.020≤d≤0.050 at the ratio d (%) from surface to certain depth
Interior control molar fraction r (%) meets formula 0.20≤r≤0.80 to suppress the anti-of positive active material-electrolyte boundary
Should.
In the present invention, each composite oxide particle has such Concentraton gradient: the concentration of metallic element M2 is from multiple
The center closing oxide particle increases to surface, and at least one element in sulfur (S), phosphorus (P) and fluorine (F) is to assemble
Presented on the surface of composite oxide particle on the surface of composite oxide particle.It may therefore be assured that positive pole
Stable and the stablizing in interface of active substance.
According to the present invention it is possible to realize high power capacity, charge/discharge cycles excellent and when being used for hot environment
Present the battery of the least deterioration.
Accompanying drawing explanation
Fig. 1 shows the perspective view of the configuration example of nonaqueous electrolyte battery according to the embodiment of the present invention;
Fig. 2 is the sectional view of the line II-II along Fig. 1 of the rolled electrode bodies shown in Fig. 1;
Fig. 3 shows the sectional view of the configuration example of nonaqueous electrolyte battery according to the embodiment of the present invention;
Fig. 4 is the sectional view of the part being illustrated in exaggerated form the rolled electrode bodies shown in Fig. 3;And
Fig. 5 shows the sectional view of the configuration example of nonaqueous electrolyte battery according to the embodiment of the present invention.
Detailed description of the invention
Now, embodiments of the present invention are described below with reference to accompanying drawings.Embodiments described below is the present invention
Instantiation, and provide simultaneously and be technically considered preferred various restriction.But, unless given in the following description
Go out and represent the description of specific restriction for the present invention, otherwise the scope of the present invention being not restricted by the embodiments.It addition,
To be described in the following sequence.
1. the first embodiment (the first example of nonaqueous electrolyte battery)
2. the second embodiment (the second example of nonaqueous electrolyte battery)
3. the 3rd embodiment (the 3rd example of nonaqueous electrolyte battery)
4. the 4th embodiment (the 4th example of nonaqueous electrolyte battery)
5. the 5th embodiment (the 5th example of nonaqueous electrolyte battery)
6. other embodiment
[summary of the present invention]
Such as cobalt acid lithium (LiCoO2) and lithium nickelate (LiNiO2) lithium-containing transition metal oxide be widely used as lithium ion
Positive active material in secondary cell.But, the problem that they exist the stability under their charged state.Especially
It is that, due to the reactive rising of the interface between positive active material and electrolyte, transiting metal component can be from positive pole
Dissolution, causes the deterioration of active substance or the metal of dissolution to separate out in negative side.As a result, the occlusion that can hinder lithium (Li) is (embedding
Enter) and release (deintercalation).
Additionally, such positive active material as mentioned above is considered to accelerate the decomposition reaction of interface electrolyte, lead
Causing form coating at the electrode surface or produce gas, it causes the deterioration of battery behavior.Meanwhile, be suitably designed positive pole-
Under conditions of negative pole ratio, by reaching the maximum charge electricity of at least 4.20V (preferably at least 4.35V, more preferably at least 4.40V)
The mode of pressure is charged, the energy density of battery when can improve charging.But, it is clear that at charging voltage liter
High and under the high charge voltage conditions of more than 4.25V in the case of recharge-discharge cycles, active substance or electrolyte
Above-mentioned deterioration accelerate, cause charge-discharge cycle life reduce or High temperature storage after performance degradation.
Therefore, the present inventor carries out extensive careful research.Through research, they send out and currently use tool
Have improvement particle surface containing lithium-metal composite oxides in the case of, the existence of the metallic compound on particle surface is to electricity
Improving of pond characteristic produces high synergy or new effect.Based on this discovery make it is desirable to provide one is for pole
The positive active material of the lithium rechargeable battery of the big characteristic improving battery and stability.
1. the first embodiment (the first example of nonaqueous electrolyte battery)
Fig. 1 shows the perspective view of the configuration example of nonaqueous electrolyte battery according to the first embodiment of the invention.
This nonaqueous electrolyte battery is such as rechargeable nonaqueous electrolytic battery.This nonaqueous electrolyte battery that global shape is flat has
Such structure, the rolled electrode bodies 10 being wherein provided with positive wire 11 and negative wire 12 is contained in membranaceous package (outward
Mould component) in 1.
The shape of positive wire 11 and negative wire 12 the most for example, rectangular plate-like, and they are such as from package 1
Inside is drawn in the same direction towards outside.Such as, positive wire 11 is made up of the metal material of such as aluminum (Al), and example
As, negative wire 12 is made up of the metal material of such as nickel (Ni).
Package 1 is stacked with this order by such as having insulating barrier, metal level and outermost layer and passes through lamination etc. each other
The laminated film of the structure adhered to is constituted.Such as, package 1 is configured to insulating barrier side and is arranged on inner side, and every pair of outer edge leads to
Cross melted or be fixed to one another by use binding agent.
Insulating barrier by such as vistanex such as polyethylene, polypropylene, modified poly ethylene, modified polypropene and they
Copolymer is constituted.Such vistanex ensures that low water penetration and air-tightness are excellent.Metal level is by aluminum, stainless
The foil-like of steel, nickel, ferrum etc. or tabular component are constituted.Outermost layer can be such as made up of or by Buddhist nun the resin being similar to insulating barrier
Dragons etc. are constituted.Such material ensures have the high intensity preventing rupturing or pierce through.Package 1 can also have except above-mentioned absolutely
Edge layer, metal level and other layer outermost.
Between each in package 1 and positive wire 11 and negative wire 12, insert adhesive film 2 for just improving
Each in pole lead-in wire 11 and negative wire 12 adhesion strength with the inside of package 1 and be used for preventing oozing of extraneous air
Thoroughly.Adhesive film 2 is by the material with each in negative wire 12 positive wire 11 with adhesion strength (fix and contact) performance
Formed.In the case of positive wire 11 and negative wire 12 are made up of above-mentioned metal material, adhesive film 2 is the most such as by polyene
Hydrocarbon resin such as polyethylene, polypropylene, modified poly ethylene, modified polypropene etc. are formed.
Fig. 2 is the sectional view along the line II-II of Fig. 1 of the rolled electrode bodies 10 shown in Fig. 1.Rolled electrode bodies 10 has wherein
The structure that positive pole 13 and negative pole 14 are stacked by barrier film 15 therebetween and electrolyte 16, and its outermost perimembranous is by protecting
Protecting band 17 is protected.
[positive pole]
Positive pole 13 such as have positive electrode collector 13A and be separately positioned on positive electrode collector 13A both sides on positive pole
Active material layer 13B.Positive electrode active material layer can be provided only on the side of positive electrode collector 13A.As positive electrode collector
13A, it is, for example possible to use the metal forming of such as aluminium foil.
Positive electrode active material layer 13B include as positive active material one or more can occlusion and release
The positive electrode of electrode reaction thing.Positive electrode active material layer 13B farther includes the conductive auxiliary agent of such as material with carbon element and such as gathers
Vinylidene or the binding agent of politef.
[positive active material]
Positive active material is such as composite oxide particle, comprises and be different from major shift in this composite oxide particle
Metal M1 also has from the center of each granule the metallic element M2 to the Concentraton gradient of the metallic element M2 on surface.Described concentration
Gradient refers to along with close to particle surface, the concentration of metallic element M2 increases.This composite oxide particle is wherein selected from sulfur
(S), at least one element X in phosphorus (P) and fluorine (F) with aggregated forms be present on the surface of composite oxide particle containing lithium
The granule of compound transition metal oxide.Incidentally, the state on lithium-compound transition metal oxide surface can be passed through
The powder observing acquisition under SEM/EDX (scanning electron microscope/energy dispersion-type X-ray spectrometer) confirms.
Metallic element M2 is not particularly limited.It is preferable, however, that composite oxide particle is prepared by such method
The granule of lithium-containing transition metal composite oxides, wherein makes metallic element M2 preexist in inside composite oxide particle, and
And make metallic element M2 with the compound of at least one element X comprised in sulfur (S), phosphorus (P) and fluorine (F) and react so that
The concentration of the metallic element M2 at particle surface raises.
Therefore, metallic element M2 is evenly distributed in inside composite oxide particle in advance, then metallic element M2
The concentration on grain surface raises, and metallic element M2 thus can be made to be uniformly present in particle surface.As a result, metallic element M2
Modified effect on grain surface can be presented to greatest extent.
Metallic element M2 preferably, based on solid solution, can replace the major shift gold in composite oxide particle inside
Belong at least one element of element M 1.It is highly preferred that metallic element M2 is to select free manganese (Mn), magnesium (Mg), aluminum (Al), nickel
(Ni), at least one element in the group that boron (B), titanium (Ti), cobalt (Co) and ferrum (Fe) form.Metallic element M2 is main in displacement
Be present in particle surface under the state of transition metal A or when being diffused into the inner side near particle surface thus in
Now to the continuous Concentraton gradient of each granular center be effective.
Incidentally, the concentration of magnesium can be by cutting the cross section of lithium-compound transition metal oxide and by Auger electricity
The distribution that sub-power spectrum art is measured radially confirms.
Additionally, for improve metallic element M2 the concentration of particle surface metallic element M2 with comprise selected from sulfur (S), phosphorus
(P) reaction of the compound of at least one element and in fluorine (F) is preferably carried out under lithium (Li) compound coexists.At Li chemical combination
Thing coexists down in the case of reacting, and can regulate the amount of Li in lithium-contained composite oxide and suppress owing to surface modification is drawn
The capacity risen reduces.
As the lithium-compound transition metal oxide within granule, it is possible to use one of various known substances.But, excellent
Selection of land, lithium-compound transition metal oxide is to have layered rock salt structure and the primary transition metal elements A constituted as it
It it is the material of at least one in nickel (Ni), cobalt (Co), manganese (Mn) and ferrum (Fe).Such material guarantee high power capacity.This
Outward, it is possible to use wherein have been incorporated into the known substance of a small amount of addition element alternatively thing based on solid solution.
Incidentally, with the composite oxide particle of the base material acting on positive pole be such as have layered rock salt structure and
The average lithium composite xoide granule formed represented by below formula (chemical formula 1).
(chemical formula 1)
LiaAbM1-bOc
In the formula, M be preferably selected from manganese (Mn), magnesium (Mg), aluminum (Al), nickel (Ni), boron (B), titanium (Ti), cobalt (Co) and
At least one element in ferrum (Fe);A, b and c are in the range of 0.2≤a≤1.4,0≤b≤1.0 and 1.8≤c≤2.2
Numeral;It addition, the component ratio of lithium changes with charge/discharge state, the value of a shown herein represents under complete discharge condition
Value.
In chemical formula (chemical formula 1), the scope of the value of a is such as 0.2≤a≤1.4.If the value of a is the least, then conduct
The layered rock salt structure of the basic crystal structure of lithium composite xoide can destroy, so that be difficult to recharge and hold
Amount can significantly reduce.On the other hand, if the value of a is too big, then lithium can diffuse to the outside of composite oxide particle, hinders subsequently
Process the control of basicity in step, and in the kneading process of anode sizing agent, finally cause the problem promoting gelation.
Incidentally, the lithium composite xoide in above formula (chemical formula 1) is arranged to have and exceedes correlation technique
Containing lithium amount.Specifically, represent that in the lithium composite xoide in above formula (chemical formula 1), the value of a of the ratio of lithium can be more than
1.2.Herein, the value of 1.2 component ratio as the lithium in the lithium composite xoide of the type the most in the related is carried out
Disclose, and due to have with a=1 in the case of identical crystal structure, obtain working effect (reference same as the present application
The earlier application of such as the applicant: Japanese Patent Publication the 2008-251434th).
Even if notationally in the lithium composite xoide of formula (chemical formula 1), the value of a of the composition of lithium is more than 1.2,
The crystal structure of lithium composite xoide is identical in the case of being also not more than 1.2 with the value of a.Even if additionally, notationally formula is (chemical
Formula 1) in the value of a of composition of lithium more than 1.2 time, if this value is not more than 1.4, then with charge-discharge cycles
The chemical state of the transition metal constituting lithium composite xoide in redox reaction is not more than the difference in the case of 1.2 with a value
The most little.
B value scope is such as 0≤b≤1.0.If the value of b decreases below this scope, the then electric discharge of positive active material
Capacity can reduce.On the other hand, if the value of b increases above this value, then the stablizing of the crystal structure of composite oxide particle
Property can reduce, cause positive active material recharge-discharge keep capacity reduce and safety reduce.
C value scope is such as 1.8≤c≤2.2.Higher than this model in the case of the value of c is less than this scope and in this value
In the case of enclosing, the stability of the crystal structure of composite oxide particle can reduce, and causes the recharge-discharge of positive active material
Keep capacity to reduce and safety reduces, and cause the discharge capacity of positive active material to reduce.
[particle diameter]
Positive active material preferably has 2.0 μm average particulate diameter to 50 μm.If average particulate diameter is less than 2.0
μm, then can occur the stripping of positive electrode active material layer in manufacturing anode process when suppressing positive electrode active material layer.Additionally, by
Surface area in the increase of positive active material, it is therefore necessary to increase conductive auxiliary agent and the addition of binding agent so that often single
The energy density of position weight is tended to be lowered.On the other hand, if average particulate diameter is more than 50 μm, then granule tends to thorn
Wear barrier film, cause short circuit.
As above preferably positive pole 13 has the thickness of no more than 250 μm.
[negative pole]
Negative pole 14 such as has negative electrode collector 14A and the negative pole being separately positioned on the both sides of negative electrode collector 14A is lived
Property material layer 14B.Negative electrode active material layer 14B can be arranged on the only side of negative electrode collector 14A.Negative electrode collector 14A
It is made up of the metal forming of the most such as Copper Foil.
Such as, negative electrode active material layer 14B be configured to contain as negative electrode active material can occlusion and release lithium
At least one negative material, and if need can comprise conductive auxiliary agent and/or binding agent.
Occlusion can include material with carbon element such as graphite, difficult graphitized carbon or easy graphite with the example of the negative material of release lithium
Changing carbon, it can individually or use with the two or more mixture in them.Additionally, two kinds that average particulate diameter is different
Above such material can use with mixture.
Can other example of negative material of occlusion and release lithium include those comprise as constitution element can be with
Lithium forms metal or the material of semimetallic elements of alloy.The instantiation of such material includes to form alloy with lithium
The simple substance of metallic element, alloy and compound and can with lithium formed alloy the simple substance of semimetallic elements, alloy and chemical combination
Thing, and its at least partly in there is the material of more than one phase in these simple substance, alloy and compound.
The example of such metal or semimetallic elements includes stannum (Sn), lead (Pb), aluminum, indium (In), silicon (Si), zinc
(Zn), antimony (Sb), bismuth (Bi), cadmium (Cd), magnesium (Mg), boron (B), gallium (Ga), germanium (Ge), arsenic (As), silver (Ag), zirconium (Zr), yttrium
And hafnium (Hf) (Y), wherein it is preferred that metal or the semimetallic elements of 14 races in long period type periodic chart, and particularly preferably
Be silicon (Si) and stannum (Sn).Silicon (Si) and stannum (Sn) have high occlusion and the ability of release lithium, thereby ensure that high-energy is close
Degree.
The example of the alloy of silicon (Si) includes that those comprise the free stannum of choosing (Sn), nickel (Ni), copper (Cu), ferrum (Fe), cobalt
(Co), manganese (Mn), zinc (Zn), indium (In), silver (Ag), titanium (Ti), germanium (Ge), bismuth (Bi), antimony (Sb) and chromium (Cr) form
At least one in group is as the alloy of the second constitution element in addition to silicon (Si).The example of the alloy of stannum (Sn) includes that
Comprise the free silicon of choosing (Si), nickel (Ni), copper (Cu), ferrum (Fe), cobalt (Co), manganese (Mn), zinc (Zn), indium (In), silver (Ag), titanium
(Ti), at least one in the group that germanium (Ge), bismuth (Bi), antimony (Sb) and chromium (Cr) form is as in addition to stannum (Sn)
The alloy of two constitution elements.
The example of the compound of silicon (Si) or stannum (Sn) includes that those comprise oxygen (O) or the compound of carbon (C), and this change
Compound can comprise one or more in above-mentioned second constitution element in addition to silicon (Si) or stannum (Sn).
[barrier film]
Barrier film 15 can be the most stable, relative to positive active material, negative electrode active material and solvent by using
Chemically stable and nonconducting any material is formed.The example of the material that herein can use includes macromolecule nonwoven
The paper-like plate of cloth, perforated membrane and glass or ceramic fibre, it can use with the form of multilayer laminated body.The most
Hole polyolefin film, it can be to have the shape of the complex of the heat proof material formed by polyimides, glass or ceramic fibre etc.
Formula uses.
[electrolyte]
Electrolyte 16 includes electrolyte and can be used for keeping the holding body of electrolyte, and this holding body includes macromolecule chemical combination
Thing, and be so-called gelation state.Electrolyte comprises electrolytic salt and can be used for dissolving the solvent of electrolytic salt.Electrolyte
The example of salt includes such as LiPF6、LiClO4、LiBF4、LiN(SO2CF3)2、LiN(SO2C2F5)2And LiAsF6Lithium salts, it can
Individually or to use with the two or more mixture in them.
The example of solvent includes the lactone of such as gamma-butyrolacton, gamma-valerolactone, δ-valerolactone, 6-caprolactone etc., such as
Ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, dimethyl carbonate, Ethyl methyl carbonate, carbonic acid diethyl
The carbonate solvent of ester etc., such as 1,2-dimethoxy-ethane, 1-ethyoxyl-2-Ethyl Methyl Ether, 1,2-diethoxyethane,
The ether solvents of oxolane, 2-methyltetrahydrofuran etc., the nonaqueous solvent of the nitrile solvent such as such as acetonitrile, such as sulfolane solvent,
The nonaqueous solvent of phosphoric acid class, phosphate ester solvent and ketopyrrolidine.These solvents can two or more individually or with in them
Mixture use.
Additionally, solvent preferably comprises the compound having a structure in which, in described structure, cyclic ester or ol ester
Hydrogen moiety or be all fluorinated (being replaced by fluorine atom).Preferably as fluorinated compound is carbonic acid two fluoroethylene
(4,5-bis-fluoro-1,3-dioxolan-2-one).Thus, even if include the chemical combination of silicon (Si), stannum (Sn), germanium (Ge) etc. in use
In the case of thing is as the negative pole 14 of negative electrode active material, it is also possible to improve charge-discharge cycles characteristic.Particularly, carbonic acid two
Fluoroethylene has the improvement effect of excellence to cycle characteristics.
Macromolecular compound can be any by lyosoption by the macromolecular compound of gelatine.Macromolecule chemical combination
The example of thing includes fluoro macromolecular compound such as Kynoar, vinylidene fluoride-hexafluoropropylene copolymer etc., ether producing high-molecular
Compound such as poly(ethylene oxide), cross linked polymer etc. containing poly(ethylene oxide), and comprise polyacrylonitrile, poly(propylene oxide) or poly-first
Base acrylic acid methyl ester. is as the macromolecular compound of repetitive.These macromolecular compounds can be individually or with in them
Two or more mixture uses.
Particularly, from the viewpoint of oxidation-reduction stability, fluoro macromolecular compound is desired, wherein comprises partially
Fluorothene and hexafluoropropene are preferred as the copolymer of component.And, copolymer can comprise the list of unsaturated dibasic acid
The ethylene halide of ester such as monomethyl maleate etc., such as trifluoro-ethylene etc., the ring of such as vinylene carbonate unsaturated compound
Shape carbonic ester or the acryloyl group vinyl monomer containing epoxide group are as component, so that it can obtain higher spy
Property.
Additionally, as solid electrolyte, it is possible to use inorganic solid electrolyte and polymer solid electrolyte, as long as this is solid
Body electrolyte has lithium-ion-conducting.The example of inorganic solid electrolyte includes lithium nitride and lithium iodide.Macromolecular solid
Body electrolyte all includes electrolytic salt and can be used for dissolving the macromolecular compound of this electrolytic salt.The example of macromolecular compound
Including ether macromolecule the most poly-(oxirane), its cross-linking products etc., poly-(methacrylate) macromolecule, acrylate polymeric
Deng, they can be used alone or as the two or more copolymer in them or with two or more the mixing in them
Compound uses.
[method manufacturing positive pole]
First, the synthesis present invention comprises the composite oxide particle of metallic element M1.For synthesizing composite oxide
The mode of grain is not particularly limited.And, as being used for making composite oxide particle and comprising selected from sulfur (S), phosphorus (P) and fluorine
(F) the compound reaction of at least one element in makes the method raised in the concentration of the metallic element M2 of particle surface, can
Use known various methods.
Additionally, the method on the surface for coating composite oxide particle includes such method, wherein by using ball
Grinding machine, crusher, pulverizer etc. make the lithium-compound transition metal oxide containing metallic element M2 and comprise selected from sulfur (S), phosphorus
(P) compound of at least one element and in fluorine (F) is pulverized, and mixes and coats (deposition).In carrying out this operation, add one
Quantitative liquid component (can be such as water) is effective.In addition it is also possible to use the coating processed by mechanochemistry (heavy
Long-pending) or by the vapor phase method such as coating (deposition) of metallic compound such as sputtering, CVD (chemical gaseous phase deposition).
And, by mixing raw material in water or in the solvent of such as ethanol, by via the knot neutralized in the liquid phase
Brilliant or by other similar approach can the upper formation of lithium-compound transition metal oxide comprise selected from sulfur (S), phosphorus (P) and
The surface of at least one element in fluorine (F).Thus making at least one element in sulfur (S), phosphorus (P) and fluorine (F)
It is present in after comprising on the lithium-compound transition metal oxide of metallic element M2, preferably carries out heat treatment and make metallic element
M2 raises in the concentration of particle surface.For example, it is possible to carry out heat treatment at 350 DEG C to 900 DEG C.Lithium-the transition metal obtained
Composite oxides can be composite oxides by the known technical finesse for controlling powder property.
Subsequently, mix to prepare positive pole by the conductive auxiliary agent of positive active material, binding agent and such as material with carbon element
Compositions.This positive electrode composition is dispersed in the solvent of such as METHYLPYRROLIDONE, to prepare positive electrode composition slurry
Material.Binding agent can be Kynoar, politef etc..
Then, this positive electrode composition slurry is applied to positive electrode collector 13A, and is dried.Afterwards, roll squeezer etc. is used
It is compressed molding to form positive electrode active material layer 13B, is derived from positive pole 13.Incidentally, if it is desired, in preparation just
The conductive auxiliary agent of such as material with carbon element is mixed during the compositions of pole.
[method manufacturing negative pole]
Then, negative pole 14 is manufactured in the following manner.First, negative electrode active material and binding agent are mixed with each other with
Prepare cathode composition, and this cathode composition is dispersed in the solvent of such as METHYLPYRROLIDONE, negative with preparation
Pole combination pulp.Subsequently, this cathode composition slurry is applied to negative electrode collector 14A, and makes solvent evaporate.It
After, use roll squeezer etc. to be compressed molding to form negative electrode active material layer 14B, be derived from negative pole 14.
[method manufacturing nonaqueous electrolyte battery]
For example, it is possible to manufacture nonaqueous electrolyte battery in the following manner.First, electrolyte, macromolecule chemical combination will be comprised
The precursor solution of thing and mixed solvent is applied in each in positive pole 13 and negative pole 14, and evaporates mixed solvent, with
Form electrode 16.Afterwards, by positive wire 11 by being welded to connect the end to positive electrode collector 13A, and by negative wire
12 by being welded to connect the end to negative electrode collector 14A.
Then, by be formed with the positive pole 13 of electrolyte 16 and negative pole 14 by barrier film 15 therebetween be stacked with
Form stacked body, this stacked body is wound along the longitudinal direction, and by protection with the 17 outermost perimembranous adhering to coiling body, with shape
Become rolled electrode bodies 10.Finally, such as, rolled electrode bodies 10 is clipped between package 1, and makes the peripheral part of package 1 lead to
Cross heat fusing etc. to be adhering to each other, to be sealed in package 1 by rolled electrode bodies 10.In this case, adhesive film 2 is inserted
Between each in each and package 1 in positive wire 11 and negative wire 12.So, complete such as Fig. 1 and
Nonaqueous electrolyte battery shown in Fig. 2.
Further, it is also possible to manufacture nonaqueous electrolyte battery in the following manner.First, positive pole 13 He is manufactured in the above described manner
Negative pole 14, and positive wire 11 and negative wire 12 are adhered to positive pole 11 and negative pole 12 respectively.Then, by positive pole 13 with negative
Pole 14 is stacked to form stacked body by barrier film 15 therebetween, winds this stacked body, and is adhered to by protection band 17
The outermost perimembranous of coiling body, to form the coiling body of the precursor as rolled electrode bodies 10.Then, this coiling body is clipped in packaging
Between part 1, the edge, periphery in addition to a side of package 1 is carried out heat fused to obtain bag shape, thus will volume
It is contained in package 1 around body.Subsequently, preparation is containing electrolyte, the monomer as the raw material for macromolecular compound, polymerization
Initiator and other material (the need to) such as the electrolyte composition of polymerization inhibitor, this electrolyte composition is introduced
In package 1.
After introducing electrolyte composition, by the peristome of the incompatible sealed package of hot melt 1 under vacuum atmosphere.Connect
, heat will be applied so that a kind of monomer or various of monomer are polymerized to form macromolecular compound, and be consequently formed gel electrolyte 16,
And assemble nonaqueous electrolyte battery as depicted in figs. 1 and 2.
The improvement details of cycle characteristics etc. is the most unclear, but it is believed that this improvement is realized by following mechanism.Filling
In the lithium rechargeable battery of electricity condition, positive pole is in Strong oxdiative state, and is in easy sending out with the electrolyte of positive contact
The environment of raw oxidation Decomposition, the most in high temperature environments.When electrolyte is decomposed, on the surface of positive active material
Form torpescence film, thus stop electronics and/or the migration of lithium ion.
And, the component of decomposition produces the molecule that activity is high in electrolyte present in the hole of electrode, thus accelerates electricity
Solve the deterioration of liquid or attack (corrosion) positive active material, thus dissolve the constitution element of positive active material or reduce capacity.
In order to suppress such phenomenon, it is insufficient for only stablizing the interface between positive active material granule and electrolyte, above-mentioned surely
It is set for using and stablize the outside of positive active material granule and its neighbouring bioactive molecule must be carried out cooperatively.
In lithium-containing transition metal oxide in embodiments of the present invention, make the master being different within oxide particle
The metallic element M2 wanting transition metal is present on particle surface so that the interface between active material particle and electrolyte is steady
Fixed.Additionally, make the lithium-compound transition metal oxide comprising at least one element in sulfur (S), phosphorus (P) and fluorine (F) with
Aggregated forms is present in the vicinity of granule so that bioactive molecule stabilisation.It is believed that due to the collaborative effect of these Stabilization
Really, battery performance is improved considerably.
Furthermore, it is believed that owing to making metallic element M2 be uniformly present in the inside of granule in advance, then make metallic element M2
Concentration at particle surface raises, to guarantee that metallic element M2 is uniformly present in particle surface, so metallic element M2
Stablizing effect can present to greatest extent, thus successfully improves battery performance.
[effect]
According to the first embodiment of the invention the nonaqueous electrolyte battery in, can suppress the deterioration of cycle characteristics, press down
Make the internal resistance owing to charge-discharge cycles causes in high temperature environments to raise, and thus can realize raising simultaneously
Capacity and the battery behavior of improvement.
2. the second embodiment (the second example of nonaqueous electrolyte battery)
Second embodiment of the present invention will be described.Nonaqueous electrolyte battery second embodiment of the invention makes
With the positive active material with evenly coating.
Owing to other material is identical with the first embodiment with structure, therefore omit the explanation about them.
[positive active material]
Positive active material is wherein to comprise be different from primary transition metal M1 and have the center from each granule
The composite oxide particle of metallic element M2 of Concentraton gradient towards the metallic element M2 on surface.Concentraton gradient refers to along with connecing
The concentration of nearly particle surface metallic element M2 increases.Composite oxide particle is the granule of lithium-containing transition metal composite oxides,
Wherein at least one element X in sulfur (S), phosphorus (P) and fluorine (F) is present in the table of composite oxide particle with aggregated forms
Face.
In this second embodiment, comprise at least one element in sulfur (S), phosphorus (P) and fluorine (F) compound or
The catabolite of this compound has the fusing point of more than 70 DEG C less than 600 DEG C.Such as utilized ball mill to be positioned at by certain way
This compound or the catabolite of this compound on the surface of composite oxides are melted by heating, thus are evenly coated with
The surface of composite oxides.Hereafter, the catabolite making heating and melted compound or this compound is anti-with composite oxides
Should.Make coating than the first embodiment more effectively and evenly.
When heating the catabolite of this compound or this compound at a temperature of higher than 600 DEG C, composite oxygen will be caused
The structure reacting and can changing composite oxides in compound.But in the present embodiment, make maybe this change of this compound
The catabolite of compound melt and coat composite oxides before changing in the structure of composite oxides with the answering of steady statue
Conjunction oxide reacts.
If the fusing point of the catabolite of this compound or this compound is higher than 600 DEG C, then at compound or product melt
And start coating reaction before coating the surface of composite oxide particle, and compound or described product and composite oxides it
Between reaction start, it only provides part coating reaction with composite oxides at position that compound or described product contact, this
Cause the disadvantageous non-homogeneous coating on composite oxides.
Heating at a temperature of more than 600 DEG C also results in the structure change of composite oxides.
If the fusing point of this compound or this catabolite is less than 70 DEG C, then this compound or this product are passing through ball mill
Deng deposition process in will adversely melt or decompose.
The catabolite of this compound or this compound preferably has the average diameter of below 30 μm.Being somebody's turn to do of such diameter
Compound or this catabolite will realize the uniform coating of composite oxides.When this compound or this catabolite diameter are the biggest
Time, they can not mix with composite oxides well to utilize ball mill etc., and it causes the nonuniform deposition on composite oxides.
The diameter of this compound or this catabolite does not has lower limit.Less diameter will provide coating evenly.But diameter is actual
On be ground into about 1 μm by this compound or this catabolite and limited.
The example of compound is diammonium phosphate ((NH4)2HPO4), ammonium dihydrogen phosphate (NH4H2PO4), ammonium sulfate ((NH4)2HPO4), phosphoric acid (H3PO4) etc..The cation of these compounds is removed by evaporating the most when heated, therefore can obtain
There is no the positive active material of impurity, its reduction that can avoid capacity and other deleterious effects.
As being different from the metallic element M2 of primary transition metal M1, the metal identical with embodiment 1 can be used
Element M 2.
[method manufacturing positive active material]
For example, it is possible to prepare the positive active material of the second embodiment according to following procedure.
First, the surface of composite oxide particle is coated with coating material.About being used for coating composite oxide particle
The illustrative methods on surface, the method identical with the first embodiment can be used, wherein by using ball mill, pulverizing
Machine, pulverizer etc. are pulverized the lithium-compound transition metal oxide comprising metallic element M1 and comprise selected from sulfur (S), phosphorus (P) and fluorine
(F) compound of at least one element X in, mixes and coats (deposition).
In carrying out this operation, it is effective for adding a certain amount of liquid component (can be such as water).In addition it is also possible to
Use the coating (deposition) processed by mechanochemistry or use metal by vapor phase method such as sputtering, CVD (chemical gaseous phase deposition) etc.
The coating (deposition) of compound.
Metallic element M1 is comprised making at least one element X in sulfur (S), phosphorus (P) and fluorine (F) thus be present in
Lithium-compound transition metal oxide on after, preferably carry out heat treatment and make metallic element M2 concentration at particle surface
Raise.For example, it is possible to carry out heat treatment at 700 to 900 DEG C.Lithium-the compound transition metal oxide that can make acquisition stands
For controlling the process of the known technology of powder property or some other purposes.
In heat treatment process, the compound being positioned on the surface of composite oxides is melt into liquid condition and makes
The combined thing in surface of composite oxides uniformly coats.After further heat treatment, compound decomposes and cation quilt
Remove, and anion is reacted with the metallic element M2 being included in composite oxides.Compound melts with coating material
The temperature of heat treatment can be raised after reaction.
[effect]
According to the second embodiment, combined oxidation can be coated with coating material before the structure of composite oxides changes
Thing.Therefore, it can improve the function of positive active material, it causes the better performance of rechargeable nonaqueous electrolytic battery.
3. the 3rd embodiment (the 3rd example of nonaqueous electrolyte battery)
Third embodiment of the present invention will be described.Nonaqueous electrolyte battery according to third embodiment of the present invention makes
The gel electrolyte 16 in nonaqueous electrolyte battery according to the first embodiment of the invention is replaced with electrolyte.In this feelings
Under condition, by using electrolyte with its dipping barrier film 15.As electrolyte, it is possible to use identical with the first embodiment
Electrolyte.
For example, it is possible to manufacture the nonaqueous electrolyte battery thus constructed in the following manner.First, manufacture positive pole 13 and bear
Pole 14.Positive pole 13 and negative pole 14 can be manufactured in the way of identical with above-mentioned first embodiment, omit system the most herein
The detailed description made.
Then, after positive wire 11 and negative wire 12 are respectively connecting to positive pole 13 and negative pole 14, by positive pole 13 He
Negative pole 14 stacks to be formed stacked body, winding layer laminate together by barrier film 15 therebetween, and protection band 17 is adhered to volume
Outermost perimembranous around body.
Result, it is thus achieved that the rolled electrode bodies identical with the structure of above-mentioned rolled electrode bodies 10, difference is, omits
Electrolyte 16.After being clipped between package 1 by coiling body, electrolyte is incorporated into the inside of package 1, and sealed bundle
Piece installing 1.By this way, it is thus achieved that according to the nonaqueous electrolyte battery of third embodiment of the present invention.
[effect]
According to third embodiment of the present invention, it is possible to obtain the effect identical with the first embodiment.Specifically, permissible
The deterioration of suppression cycle characteristics, suppresses the rising due to the internal resistance that charge-discharge cycles causes in high temperature environments, and
Thus can realize capacity and the battery behavior of improvement improved simultaneously.
4. the 4th embodiment (the 4th example of nonaqueous electrolyte battery)
Then, the structure of the nonaqueous electrolyte battery of the 4th embodiment according to the present invention will be described with reference to Fig. 3 and Fig. 4
Make.Fig. 3 shows the structure of the nonaqueous electrolyte battery of the 4th embodiment according to the present invention.
This nonaqueous electrolyte battery is so-called cylindrical battery, wherein winding banding positive pole 31 and banding negative pole 32 and
Barrier film 33 between them forms rolled electrode bodies 30, and this rolled electrode bodies 30 is arranged on substantially hollow cylindrical battery shell
The inside of 21.
Barrier film 33 is impregnated with the electrolyte as liquid electrolyte.Battery case 21 is by ferrum (Fe) shape of such as nickel plating (Ni)
Become.Battery case 21 is closed at its end, and is unlimited at its other end.In the inside of battery case 21, by a pair insulation board
22 and 23 outer peripheral faces being respectively perpendicular to rolled electrode bodies 30 are arranged on the two opposite sides of rolled electrode bodies 30.
At the opening of battery case 21, battery cover 24 and be arranged on relief valve mechanism 25 He inside this battery cover 24
PTC (positive temperature coefficient) thermistor element 26 is installed by utilizing packing ring 27 caulked.Thus, sealed cell shell 21 is interior
Portion.
Battery cover 24 is made up of such as identical with battery case 21 material.Relief valve mechanism 25 is by thermistor element 26
And electrically connect with battery cover 24.This relief valve mechanism 25 is configured in making battery due to internal short-circuit or external heat
When portion's pressure exceedes predetermined value, discoid plate 25A upset is to cut off the electrical connection between battery cover 24 and rolled electrode bodies 30.
When the temperature increases, thermistor element 26 limits electric current by increasing its resistance, thus prevents by big electric current
The abnormal heating caused.Packing ring 27 is formed by such as insulant, and its surface-coated has Colophonium.
Such as, rolled electrode bodies 30 winds centered by centrepin 34.In rolled electrode bodies 30, will be by shapes such as aluminum (Al)
The positive wire 35 become is connected to positive pole 31, and the negative wire 36 formed by nickel (Ni) etc. is connected to negative pole 32.Make positive pole
Lead-in wire 35 is electrically connected to battery cover 24 by being soldered to relief valve mechanism 25, and makes negative wire 36 by being soldered to battery case
21 and be electrically connected to battery case 21.
Fig. 4 is the sectional view of the part showing the electric collective 30 of the winding shown in Fig. 3 in the way to enlarge.Winding electricity collection
Body 30 has a structure in which, wherein positive pole 31 and negative pole 32 are stacked to form stacking by barrier film 33 therebetween
Body, and wind this stacked body.
Positive pole 31 includes that such as positive electrode collector 31A and the positive pole being separately positioned on the both sides of positive electrode collector 31A are lived
Property material layer 31B.It is negative be separately positioned on the both sides of negative electrode collector 31A that negative pole 32 includes such as negative electrode collector 32A
Pole active material layer 32B.Positive electrode collector 31A, positive electrode active material layer 31B, negative electrode collector 32A, negative electrode active material layer
The composition of 32B, barrier film 33 and electrolyte is respectively equivalent to the positive electrode collector 13A in above-mentioned first battery, positive electrode active material
Those of matter layer 13B, negative electrode collector 14A, negative electrode active material layer 14B, barrier film 15 and electrolyte are constituted.
[method manufacturing nonaqueous electrolyte battery]
Now, the method that will be described below the nonaqueous electrolyte battery manufacturing the 4th embodiment according to the present invention.
Positive pole 31 is manufactured as got off.First, it is mixed with each other to prepare positive electrode composition by positive active material and binding agent, by this positive pole
Compositions is dispersed in the solvent of such as METHYLPYRROLIDONE, to prepare positive electrode composition slurry.Then, by this positive pole
Combination pulp is applied to positive electrode collector 31A, and is dried.Afterwards, roll squeezer etc. is used to be compressed molding just to be formed
Pole active material layer 31B, is derived from positive pole 31.
Manufacture negative pole 32 in the following manner.First, negative electrode active material and binding agent are mixed with each other with preparation
Cathode composition, is dispersed in this cathode composition in the solvent of such as METHYLPYRROLIDONE, to prepare cathode composition
Slurry.Then, this cathode composition slurry is applied to negative electrode collector 32A, and makes solvent evaporate.Afterwards, roll-in is used
Machines etc. are compressed molding to form negative electrode active material layer 32B, are derived from negative pole 32.
Subsequently, positive wire 35 is connected to positive electrode collector 31A by welding etc., and by negative wire 36 by welding
Etc. being connected to negative electrode collector 32A.Afterwards, winding positive pole 31 and negative pole 32 and the stacked body of the barrier film between them 33, will
The top ends of positive wire 35 is soldered to relief valve mechanism 25, and the top ends of negative wire 36 is soldered to battery case 21.
Then, the stacked body of positive pole 31 and negative pole 32 is clipped between a pair insulation board 22 and 23, and is contained in battery
In shell 21.After positive pole 31 and negative pole 32 being contained in battery case 21, electrolyte is incorporated into the inside of battery case 21 so that
Barrier film 33 impregnates electrolyte.
Afterwards, by battery cover 24, relief valve mechanism 25 and thermistor element 26 by being fixed to packing ring 27 caulked
The open end of battery case 21.By this way, the nonaqueous electrolyte battery shown in Fig. 3 has been manufactured.
[effect]
In the nonaqueous electrolyte battery of the 4th embodiment according to the present invention, gas can be suppressed to generate, and prevent
Only raise, due to internal pressure, the cell fracture caused.
5. the 5th embodiment (the 5th example of nonaqueous electrolyte battery)
The nonaqueous electrolyte battery of the 5th embodiment according to the present invention uses the positive-active with evenly coating
Material, replaces the positive active material in the nonaqueous electrolyte battery of the 4th embodiment.
Owing to other material is identical with the 4th embodiment with composition, therefore omit the explanation about them.
[positive active material]
Meet in the range of 0.020≤d≤0.050 at the ratio d (%) from surface to certain depth, the 5th embodiment
Molar fraction r (%) of positive active material meet formula 0.20≤r≤0.80.Ratio d and molar fraction r are according to following
Formula determines.
Ratio d (%)=[(quality of primary transition metal M1)+(quality of metallic element M2)]/(matter that granule is overall
Amount) (I)
Molar fraction r=(the material amount of metallic element M2)/[(the material amount of primary transition metal M1)+(metallic element M2
Material amount)] (II)
In addition to above-mentioned point, the positive active material of the 5th embodiment and the 4th embodiment identical.
The quality of primary transition metal M1 and the quality of metallic element M2 can be known as follows: be combined by lithium-transition metal
The surface of oxide is dissolved in buffer solvent, analyzes the primary transition metal M1 and metallic element M2 being dissolved in buffer solvent
Mass content.
Specifically, ratio d (%) and molar fraction ratio r can determine as got off.First, buffer solvent is joined
In lithium-compound transition metal oxide granule and mix them.Then, Sample buffer solvent the most at regular intervals, and mistake
Filter solvent.The quality of the primary transition metal M1 being included in each buffer solvent by inductively coupled plasma method measurement and
The quality of metallic element M2.
Calculate the amount [mol] of metal M1 and metallic element M2 according to described quality, and obtain according to formula (I) and (II)
Ratio d and molar fraction r.Herein, granule is assumed to spherical, and exists at the diameter supposing the granule being dissolved in buffer solvent
Keep becoming under spherical state less under conditions of calculate.
The above-mentioned analysis on the surface of positive active material is three-dimensional, and can provide the quantitative analysis of Concentraton gradient,
It is difficult to be realized by the conventional method of analysis of the apparent condition of positive active material.
Under conditions of molar fraction ratio r (%) falls in the range of 0.20≤r≤0.80, wherein, from surface to one
The ratio d (%) of depthkeeping degree meets 0.020≤d≤0.050, and capability retention and High temperature storage capacity are higher.
Even if but molar fraction ratio r (%) falls in the range of 0.20≤r≤0.80, wherein, from surface to necessarily
The ratio d (%) of the degree of depth is also unsatisfactory for 0.020≤d≤0.050, exists and not necessarily has capability retention and high temperature dwell sustainability
Improve the trend of effect.
Preferably, the ratio d (%) from surface to certain depth meets in the range of 0.020≤d≤0.050, molar ratio r
(%) reduce from surface to inside, because capability retention and the reduction of high temperature dwell sustainability can be avoided, especially can be notable
Avoid the reduction of capability retention.
Except the molar fraction ratio r when the ratio d (%) from surface to certain depth meets 0.020≤d≤0.050
(%), outside falling in the range of 0.20≤r≤0.80, further preferably 0.010 is met at the ratio d (%) from surface to certain depth
≤ d < in the range of 0.020, molar ratio r meets 0.55≤r≤1.0 because can avoid discharge capacity reduction and can
To improve cycle performance and High temperature storage performance.
[method manufacturing battery]
The method of the rechargeable nonaqueous electrolytic battery manufacturing the 5th embodiment is as follows.
First, the lithium-compound transition metal oxide granule making to comprise lithium, primary transition metal M1 and metallic element M2 with
The compound comprising at least one element X in sulfur (S), phosphorus (P) and fluorine (F) mixes.Preferably further mixing comprises lithium
Compound.Then, at least one unit realizing comprising in sulfur (S), phosphorus (P) and fluorine (F) is processed by mechanochemistry
The compound of element X and preferably comprise the compound of the lithium deposition on the surface of lithium-compound transition metal oxide.To mixing
Thing mechanochemistry processes more than 5 minutes less than 2 hours.When mechanochemistry processes and is shorter than 5 minutes, coating is not enough, and just
Pole active material particle is ground into the less granule with too minor diameter.
Then, lithium-compound transition metal oxide granule is fired, to obtain positive active material.For the temperature fired
It is preferably 500 DEG C to 1500 DEG C.If temperature is less than 500 DEG C, then lithium-compound transition metal oxide granule can not be fully coated with
Cover.But, if temperature is higher than 1500 DEG C, then particle aggregation becomes second particle, and it causes the coating on collector body to be deteriorated.
After burning till, lithium-compound transition metal oxide granule has the metal on the centrally directed surface from each granule
The Concentraton gradient of element M 2.Granule comprise with aggregated forms be deposited on the surface of composite oxide particle selected from sulfur (S), phosphorus
(P) at least one element X and in fluorine (F).
Generally, molar ratio r can comprise at least one element X in sulfur (S), phosphorus (P) and fluorine (F) by employing
The addition of compound regulate.When compound adds very little, reaction is so small that and can not obtain enough coatings, and
Molar ratio r reduces.When addition is bigger, molar ratio r becomes relatively big, but is not more than 1 in r principle.Reaction is from table
Face is carried out to inside, therefore when addition is bigger, the part bigger for ratio d (%) from surface to certain depth obtains height
Molar ratio.
When coating material (i.e. compound or catabolite) and base material (i.e. lithium-compound transition metal oxide) are the most fine
During mixing, molar fraction ratio r reduces.Such as, more than a diameter of 100 μm of compound, it is more than positive active material 5 μm extremely
The average diameter of 30 μm, and non-homogeneous dispersion.Therefore, there is no preferred coating state, and molar fraction ratio r has
Time become relatively low.About the technology of mixing, any technology can be used, as long as base material and coating material mix well,
The preliminary technology etc. of the mixture in such as planetary-type mixer, shake bag.
After obtaining positive active material, the program identical with the 4th embodiment can be taked to obtain the 5th enforcement
The nonaqueous electrolyte battery of mode.
The upper limit of the charging voltage of the battery of the 4th embodiment can be 4.2V, but is preferably designed to higher than 4.2V.
Particularly, design battery makes the upper limit of charging voltage be preferably 4.25V to 4.80V, more excellent from the viewpoint of discharge capacity
Select more than 4.35V, be below 4.65V from a security point of view.The lower limit of the discharge voltage of battery is preferably 2.00V extremely
3.30V.Design high cell voltage and cause high-energy-density.
6. other embodiment (deformation)
The present invention is not limited to the above-mentioned embodiment of the present invention, and the most various deformation and application
It is possible.Such as, the shape of nonaqueous electrolyte battery is not limited to the above-mentioned type (column type), and can be such as coin
Type.
Additionally, it is, for example possible to use include the polymer solid electrolyte of ionic conductive high molecular material or include ion
The inorganic solid electrolyte of conducting inorganic material is as electrolyte.The example of ionic conductive high molecular material includes polyethers, gathers
Esters, polyphosphazene and polysiloxanes.The example of inorganic solid electrolyte includes ionic conductivity ceramics, ion conductive crystal and ion
Electro-conductive glass.
The positive active material of the 5th embodiment can be used in the battery of the first to the 3rd embodiment.
[embodiment]
Now, will be specifically described the present invention by the embodiment illustrated, these embodiments are not construed as this
Bright restriction.
In embodiment 1-1 to 1-13 and comparative example 1-1 to 1-9, change the interpolation volume of coating material, and determine tool
There is the battery performance of the positive electrode that the distribution of coating material is different on the surface of composite oxides.
<embodiment 1-1>
[manufacture of positive pole]
At the molar ratio mixed carbonic acid lithium (Li with Li:Co:Al:Mg=1.00:0.98:0.01:0.012CO3), oxidation
Cobalt (Co3O4), aluminium hydroxide (Al (OH)3) and magnesium carbonate (MgCO3After), at 900 DEG C, burn till mixture in atmosphere 5 hours,
To obtain lithium-cobalt composite oxide (LiCo0.98Al0.01Mg0.01O2).The average particulate diameter of lithium-cobalt composite oxide is by swashing
Light scattering method is measured, and is 13 μm.
Subsequently, lithium carbonate (Li is weighed2CO3) and diammonium phosphate ((NH4)2HPO4) and and lithium-cobalt composite oxide
(LiCo0.98Al0.01Mg0.01O2) mixing, in order to obtain the atom ratio of Co:Li:P=98:1:1.Then, mechanochemistry is passed through
System processes the mixing material 1 hour comprising lithium-cobalt composite oxide.Result, it is thus achieved that the precursor before firing, wherein lithium-cobalt
The granule of composite oxides exists as center material, and lithium carbonate and diammonium phosphate deposit at the surface of the particles.
With the speed of 3 DEG C/min, the precursor before firing is heated up, and be maintained at 900 DEG C 3 hours, the most slowly
Cooling, to obtain the lithium-compound transition metal oxide belonging to the present invention.This lithium-compound transition metal oxide has uniformly
The magnesium (Mg) being distributed on the surface of lithium-cobalt composite oxide granule.Additionally, the concentration of magnesium (Mg) ratio on the surface of granule exists
Height, and lithium phosphate (Li are wanted in the inside of granule3PO4) spread at the surface of the particles.
Incidentally, the apparent condition of lithium-compound transition metal oxide is by observing the powder of acquisition under SEM/EDX
Confirm.It was confirmed magnesium (Mg) being uniformly distributed at the surface of the particles behind the surface observing lithium-compound transition metal oxide
With phosphorus distribution at the surface of the particles.Additionally, the concentration of magnesium is by cutting the cross section of lithium-compound transition metal oxide, and lead to
Cross auger electron spectrometry Elemental redistribution radially to confirm.In the cross section measuring lithium-compound transition metal oxide
After Elemental redistribution, the concentration of magnesium is proved to be from the surface of granule internally consecutive variations.
Additionally, when by using measurement that CuK α carries out x-ray diffractogram of powder case to powder, except being equivalent to have
The LiCoO of layered rock salt structure2Diffraction maximum outside, have also demonstrated and be equivalent to Li3PO4Diffraction maximum.
By using lithium-compound transition metal oxide obtained as described above as positive active material, manufacture non-water power
Solve electrolitc secondary cell, and the high-temperature cycle that have rated battery as described below and internal resistance change.
By mixing the above-mentioned positive active material of 98wt%, the amorphous carbon powder (Ketjen black) of 0.8wt% and
The Kynoar (PVdF) of 1.2wt% prepares positive electrode composition.This positive electrode composition is dispersed in N-methyl-2-pyrrolidine
To prepare positive electrode composition slurry in ketone (NMP), then it is applied to equably the positive electrode collector being made up of banding aluminium foil
Both sides.Subsequently, current of warm air is dried the positive electrode composition slurry on the surface of positive electrode collector, and uses roll squeezer to enter
Row compression forming, to form positive electrode composition layer.
[manufacture of negative pole]
Cathode composition is prepared by the powdered graphite of mixing 95wt% and the PVdF of 5wt%.By this cathode composition
It is dispersed in METHYLPYRROLIDONE to prepare cathode composition slurry, then it is applied to equably by banding Copper Foil
The both sides of the negative electrode collector constituted, are pressed, the most under heating to form cathode composition layer.
[preparation of electrolyte]
At the mixed solvent by obtaining with the volume mixture ethylene carbonate (EC) of 1:1 and Ethyl methyl carbonate (MEC)
In, dissolve lithium hexafluoro phosphate (LiPF6) to obtain 1mol/dm3Concentration, thus prepare nonaqueous electrolytic solution.
[assembling of battery]
By banding positive pole manufactured as above and negative pole and the barrier film being made up of porous polyolefin between them to be stacked on
State together winds repeatedly, thus manufactures spiral wound electrode body.Be contained in by this rolled electrode bodies by nickel plating is iron
In the battery case become, and insulation board is arranged on rolled electrode bodies above and below.Then, will be connected with negative electrode collector
The negative terminal of nickel be soldered to the bottom of battery case.Additionally, the positive terminal of the aluminum being connected with positive electrode collector is welded
It is connected to guarantee the protuberance of the relief valve with battery cover conductivity.
Finally, nonaqueous electrolytic solution is incorporated into the most it is combined with in the battery case of rolled electrode bodies.Afterwards, can pass through
Insulated enclosure packing ring is used to carry out caulked battery case, with standing valve, PTC thermistor element and battery cover.By this way, manufacture
There is 18mm external diameter and the cylindrical battery of 65mm height.
[evaluation of battery]
(a) initial capacity
In the environment of the environment temperature of 45 DEG C, cylindrical battery manufactured as above is carried out perseverance with the charging current of 1.5A
Electric current charging is until the charging voltage of 4.35V.Then, constant current charge conversion is charged to constant voltage, and when always charging
Between reach 2.5 little complete charge constantly.With the discharge current of 2.0A, battery is discharged the most immediately, and work as cell voltage
It is reduced to during 3.0V terminate electric discharge.Measurement discharge capacity in this case, as initial capacity, is found to be 9.1Wh.
(b) capability retention
With with repeat to fill to battery for measuring recharge-discharge condition identical in the above-mentioned situation of initial capacity
Electricity-discharge cycles.After circulating at 300 times, measure discharge capacity, and determine capability retention based on initial capacity.Capacity
Conservation rate is 82%.
<embodiment 1-2>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, during charging
Cell voltage be 4.20V.When evaluating battery, discovery initial capacity is 8.0Wh, and capability retention is 82%.In passing
Mention, the concentration distribution of the element in positive active material in embodiment 1-2 and latter embodiments and comparative example and living
The apparent condition of the granule of property material is shown in table 1 below.
<embodiment 1-3>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, during charging
Cell voltage be 4.4V.When evaluating battery, discovery initial capacity is 9.4Wh, and capability retention is 80%.
<embodiment 1-4>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, during charging
Cell voltage be 4.5V.When evaluating battery, discovery initial capacity is 10.0Wh, and capability retention is 61%.
<embodiment 1-5>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, to be deposited
At lithium-cobalt composite oxide (LiCo0.98Al0.01Mg0.01O2Coating material on) is ammonium dihydrogen phosphate (NH4H2PO4).Evaluating
During battery, discovery initial capacity is 9.1Wh, and capability retention is 80%.
<embodiment 1-6>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, to be deposited
At lithium-cobalt composite oxide (LiCo0.98Al0.01Mg0.01O2Coating material on) is lithium hexafluoro phosphate (LiPF6) and burn till temperature
Degree is 700 DEG C.When evaluating battery, discovery initial capacity is 9.1Wh, and capability retention is 81%.
<embodiment 1-7>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, to be deposited
At lithium-cobalt composite oxide (LiCo0.98Al0.01Mg0.01O2Coating material on) is LiBF4 (LiBF4) and burn till temperature
Degree is 700 DEG C.When evaluating battery, discovery initial capacity is 9.1Wh, and capability retention is 76%.
<embodiment 1-8>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, to be deposited
At lithium-cobalt composite oxide (LiCo0.98Al0.01Mg0.01O2Coating material on) is sulfur (S) and firing temperature is 700 DEG C.
When evaluating battery, discovery initial capacity is 9.1Wh, and capability retention is 64%.
<embodiment 1-9>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, with Co:
The atomic ratio mixing lithium-cobalt composite oxide (LiCo of Li:P=98:0.5:0.50.98Al0.01Mg0.01O2), lithium carbonate
(Li2CO3) and diammonium phosphate ((NH4)2HPO4).When evaluating battery, discovery initial capacity is 9.1Wh, and capacity keeps
Rate is 80%.
<embodiment 1-10>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, with Co:
The atomic ratio mixing lithium-cobalt composite oxide (LiCo of Li:P=98:2.5:2.50.98Al0.01Mg0.01O2), lithium carbonate
(Li2CO3) and diammonium phosphate ((NH4)2HPO4).When evaluating battery, discovery initial capacity is 8.9Wh, and capacity keeps
Rate is 75%.
<embodiment 1-11>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, with Co:
The atomic ratio mixing lithium-cobalt composite oxide (LiCo of Li:P=98:5:50.98Al0.01Mg0.01O2), lithium carbonate (Li2CO3) and
Diammonium phosphate ((NH4)2HPO4).When evaluating battery, discovery initial capacity is 8.2Wh, and capability retention is 69%.
<embodiment 1-12>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, lithium-cobalt
Composite oxides consist of LiCo0.97Al0.01Mg0.02O2.When evaluating battery, discovery initial capacity is 9.0Wh, and holds
Amount conservation rate is 84%.
<embodiment 1-13>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, lithium-cobalt
Composite oxides consist of LiCo0.95Al0.01Mg0.04O2.When evaluating battery, discovery initial capacity is 8.8Wh, and holds
Amount conservation rate is 82%.
<comparative example 1-1>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, omits
Lithium-cobalt composite oxide (LiCo0.98Al0.01Mg0.01O2) coating processing.When evaluating battery, find that initial capacity is
9.2Wh, and capability retention is 31%.
<comparative example 1-2>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, omits
Lithium-cobalt composite oxide (LiCo0.98Al0.01Mg0.01O2) coating processing and cell voltage when charging be 4.2V.Commenting
During valency battery, discovery initial capacity is 8.1Wh, and capability retention is 71%.
<comparative example 1-3>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, omits
Lithium-cobalt composite oxide (LiCo0.98Al0.01Mg0.01O2) coating processing and cell voltage when charging be 4.4V.Commenting
During valency battery, discovery initial capacity is 9.5Wh, and capability retention is 25%.
<comparative example 1-4>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, lithium-cobalt
Composite oxides consist of LiCoO2, to be deposited on lithium-cobalt composite oxide (LiCoO2Coating material on) is lithium carbonate
(Li2CO3), magnesium carbonate (MgCO3) and diammonium phosphate ((NH4)2HPO4) mixture, and weigh and mix lithium-cobalt be combined
Oxide (LiCoO2), lithium carbonate (Li2CO3), magnesium carbonate (MgCO3) and ammonium dihydrogen phosphate (NH4H2PO4), to obtain Co:Li:
The atom ratio of Mg:P=100:1:1:1.When evaluating battery, discovery initial capacity is 9.1Wh, and capability retention is
32%.
<comparative example 1-5>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, lithium-cobalt
Composite oxides consist of LiCoO2, to be deposited on lithium-cobalt composite oxide (LiCoO2Coating material on) is aluminium fluoride
(AlF3), and weigh and mix lithium-cobalt composite oxide (LiCoO2) and aluminium fluoride (AlF3), to obtain Co:Al=100:1
Atom ratio.When evaluating battery, discovery initial capacity is 9.1Wh, and capability retention is 30%.
<comparative example 1-6>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, lithium-cobalt
Composite oxides consist of LiCoO2, to be deposited on lithium-cobalt composite oxide (LiCoO2Coating material on) is aluminum phosphate
(AlPO4), and weigh and mix lithium-cobalt composite oxide (LiCoO2) and aluminum phosphate (AlPO4), to obtain Co:Al=100:
The atom ratio of 1.When evaluating battery, discovery initial capacity is 9.1Wh, and capability retention is 25%.
<comparative example 1-7>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, lithium-cobalt
Composite oxides consist of LiCoO2.When evaluating battery, discovery initial capacity is 9.1Wh, and capability retention is
20%.
<comparative example 1-8>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, lithium-cobalt
Composite oxides consist of LiCoO2, to be deposited on lithium-cobalt composite oxide (LiCoO2Coating material on) is lithium phosphate
(Li3PO4), and weigh and mix lithium-cobalt composite oxide (LiCoO2) and lithium phosphate (Li3PO4), to obtain Co:P=100:
The atom ratio of 1.When evaluating battery, discovery initial capacity is 9.1Wh, and capability retention is 15%.
<comparative example 1-9>
Manufacturing rechargeable nonaqueous electrolytic battery in the way of identical with embodiment 1-1, difference is, with phosphorus
Acid hydrogen diammonium ((NH4)2HPO4) firing temperature in sintering process is 300 DEG C after the process that coats.When evaluating battery, send out
Existing initial capacity is 8.6Wh, and capability retention is 35%.
Evaluation result is shown in table 1 below.
From evaluation result it can be seen that utilize positive active material to make magnesium (Mg) with from composite oxide particle wherein
Inside be uniformly distributed to surface, and the mode of particle surface coats the sulfur (S) so that having spread state, phosphorus (P) etc.
Embodiment can realize capability retention and good initial capacity.
On the other hand, the most do not exist in the comparative example 1-1 to 1-3 of coating material, due to battery charging capacity more
Height, therefore capability retention is significantly more reduced.Additionally, the magnesium (Mg) in oxide particle wherein is pockety
In comparative example 1-4 to 1-6, even if there is Concentraton gradient, high power capacity conservation rate can not be kept.And, there is not above-mentioned gold
In the case of belonging to element M 2, even if sulfur (S), phosphorus (P) etc. are dispersed on the surface of oxide particle, capability retention is the lowest.
In embodiment 2-1 to 2-9, change coating material and obtain the coating with the surface at composite oxides
The battery performance of the positive electrode that material is different.
<embodiment 2-1>
Manufacture the rechargeable nonaqueous electrolytic battery identical with embodiment 1-1, and with the side identical with embodiment 1-1
Formula utilizes the charging voltage of 4.35V to be evaluated, and difference is, replaces lithium carbonate and diammonium phosphate, will have and pass through
The average diameter of 10 μm that laser scattering method is measured and the diammonium phosphate ((NH of the fusing point of 190 DEG C4)2HPO4) it is deposited on lithium-cobalt
Composite oxides (LiCo0.98Al0.01Mg0.01O2On).Initial capacity is 9.1Wh and capability retention is 85%.< embodiment
2-2>
Manufacturing the rechargeable nonaqueous electrolytic battery identical with embodiment 2-1, difference is, will have and pass through laser
The average diameter of 10 μm that scattering method is measured and the ammonium sulfate ((NH of the fusing point of 513 DEG C4)2HSO4) it is deposited on lithium-cobalt combined oxidation
Thing (LiCo0.98Al0.01Mg0.01O2On).Initial capacity is 9.1Wh and capability retention is 87%.
<embodiment 2-3>
Manufacturing the rechargeable nonaqueous electrolytic battery identical with embodiment 2-1, difference is, will have and pass through laser
The average diameter of 30 μm that scattering method is measured and the diammonium phosphate ((NH of the fusing point of 190 DEG C4)2HPO4) be deposited on lithium-cobalt be combined
Oxide (LiCo0.98Al0.01Mg0.01O2On).Initial capacity is 9.1Wh and capability retention is 80%.
<embodiment 2-4>
Manufacturing the rechargeable nonaqueous electrolytic battery identical with embodiment 2-1, difference is, coating lithium-cobalt is combined
Oxide (LiNi0.79Co0.19Al0.01Mg0.01O2).Initial capacity is 10.9Wh and capability retention is 81%.
<embodiment 2-5>
Manufacturing the rechargeable nonaqueous electrolytic battery identical with embodiment 2-1, difference is, coating lithium-cobalt is combined
Oxide (LiNi0.49Co0.19Mn0.29Al0.01Mg0.01O2).Initial capacity is 9.5Wh and capability retention is 80%.
<embodiment 2-6>
Manufacturing the rechargeable nonaqueous electrolytic battery identical with embodiment 2-1, difference is, will have and pass through laser
The average diameter of 10 μm that scattering method is measured and the phosphoric acid (H of the fusing point of 43 DEG C3PO4) it is deposited on lithium-cobalt composite oxide
(LiCo0.98Al0.01Mg0.01O2On).Initial capacity is 9.1Wh and capability retention is 53%.
<embodiment 2-7>
Manufacturing the rechargeable nonaqueous electrolytic battery identical with embodiment 2-1, difference is, will have and pass through laser
The average diameter of 10 μm that scattering method is measured and the iron sulfate (Fe of the fusing point of 480 DEG C2(SO4)3) it is deposited on lithium-cobalt combined oxidation
Thing (LiCo0.98Al0.01Mg0.01O2On).Initial capacity is 8.9Wh and capability retention is 80%.
<embodiment 2-8>
Manufacturing the rechargeable nonaqueous electrolytic battery identical with embodiment 2-1, difference is, will have and pass through laser
The average diameter of 100 μm that scattering method is measured and the diammonium phosphate ((NH of the fusing point of 190 DEG C4)2HPO4) to be deposited on lithium-cobalt multiple
Close oxide (LiCo0.98Al0.01Mg0.01O2On).Initial capacity is 9.1Wh and capability retention is 58%.
<embodiment 2-9>
Manufacturing the rechargeable nonaqueous electrolytic battery identical with embodiment 2-1, difference is, will have and pass through laser
The average diameter of 100 μm that scattering method is measured and the diammonium phosphate ((NH of the fusing point of 837 DEG C4)2HPO4) to be deposited on lithium-cobalt multiple
Close oxide (LiCo0.98Al0.01Mg0.01O2On).Initial capacity is 9.0Wh and capability retention is 60%.
Evaluation result is shown in table 2 below.In table 2, further it is shown that for the result of the comparative example 1-1 of reference.
From evaluation result it can be seen that comprise wherein phosphorus P or the compound of fluorine F or pyrolysis compound have 80 DEG C to
In the embodiment 2-1 to 2-5 of the fusing point of 600 DEG C, it is possible to achieve capability retention.Assume that when burning till at 900 DEG C, bag
Phosphorous P or the compound of fluorine F or pyrolysis compound become liquid and are evenly coated with the surface of composite oxides.Real at these
Executing in example, because ammonium evaporates and is not retained in active substance, therefore initial capacity keeps the highest.
In embodiment 2-4 and 2-5, make when using lithium-nickel-cobalt composite oxides or lithium-nickel-cobalt manganese composite oxide
During for the center material of positive active material, it is possible to obtain there is the concentration so that metallic element M2 from composite oxide particle
Concentraton gradient that center increases to surface and the positive active material of good capability retention.
About embodiment 2-6, capability retention is improved, but is not the biggest owing to coating the improvement caused.Cause
Dissolve for phosphoric acid in mechanochemistry processing procedure and coating does not has those in embodiment 2-1 to 2-5 effective.This is because
The temperature that the fusing point of phosphoric acid processes less than mechanochemistry causes.
About embodiment 2-7, owing to the fusing point of compound falls in the range of 70 DEG C to 600 DEG C, coating preferably, but divides
The material solved is retained on positive electrode surface, and because this impurity is helpless to charge or discharge reaction, so initial discharge capacity
Somewhat reduce.
In embodiment 2-8, because the diameter of coating material is too big, coating material does not mixes well with composite oxides
Close.Therefore, capability retention improves, but is not the biggest owing to coating the improvement caused.Because the fusing point of coating material is 837
DEG C, higher than 600 DEG C and close to firing temperature, this causes melted at coating material and preferably coats these composite oxides
Before, coating material reacts with the region of composite oxides, and destroys well applied.
In embodiment 3-1 to 3-14 and comparative example 3-1 to 3-14, change ratio d and molar fraction ratio r and really
Determine battery behavior.
In these embodiments, ratio d obtained as below and molar fraction ratio r.
[ratio d and molar fraction ratio r]
Lithium-transition metal that the buffer solvent being prepared as pH 5.1 with citric acid and sodium citrate joins 0.2g is combined
In oxide.Stirring mixture and per minute by 0.2 μm filter filtered sample.It is included in the major shift in each sample
The quality of metal M1 (i.e. Co) or volumetric concentration and the quality of metallic element M2 (i.e. Mg, Mn, Ni) or volumetric concentration pass through ICP-
AES: inductively coupled plasma atomic emission spectrometry [HORIBA JY238 ULTRACE] is measured and is dissolved in obtain
The quality of M1 and M2 in the buffer solvent of 10mL.Utilize this result, calculate the amount [mol] of M1 and M2.According to formula (I) and
(II) ratio d and molar fraction ratio r are determined.
Ratio d (%)=[(quality of primary transition metal M1)+(quality of metallic element M2)]/(matter that granule is overall
Amount) (I)
Molar fraction r=(the material amount of metallic element M2)/[(the material amount of primary transition metal M1)+(metallic element M2
Material amount)] (II)
For capability retention and high temperature dwell sustainability, the coating including M2 is maximally effective, and wherein ratio d is full
Foot 0.20≤r≤0.80, i.e. 10nm to the 100nm degree of depth from surface.In the examples below, molar fraction ratio r along with than
Rate d changes in the range of 0.20≤r≤0.80 and have detected the battery performance of each battery.
In the examples below, metallic element M2 identified below and the distribution of element X.
[metallic element M2 and the distribution of element X]
Mg is checked, to confirm whether Mg is evenly distributed on the surface of granule or whether P is dispersed in by SEM/EDX
On surface.Cut granule, and by Auger electron spectroscopy measure along diameter Elemental redistribution with observe Mg concentration company
Continuous change.
<embodiment 3-1>
Prepare positive active material as follows.
The precursor that burns till in the way of identical with the embodiment 1-1 speed with 3 DEG C/min will be used for heating up, and
And be maintained at 900 DEG C 3 hours, then Slow cooling, to obtain lithium-compound transition metal oxide.This lithium-transition metal is multiple
Close oxide and there is the magnesium (Mg) on the surface being evenly distributed on lithium-cobalt composite oxide granule.Additionally, the concentration of magnesium (Mg) exists
The surface ratio of granule wants height, and lithium phosphate (Li in the inside of granule3PO4) spread at the surface of the particles.
It addition, confirm the surface concentration gradient of magnesium Mg in detail.Ratio d=0.02%, under 0.05% mole point
Percentage r is respectively 0.32,0.30.Be respectively 0.46 in ratio d=0.01%, molar fraction ratio r under 0.10%,
0.25。
The apparent condition of lithium-compound transition metal oxide confirms by observing the powder of acquisition under SEM/EDX.?
Observe lithium-compound transition metal oxide surface time it was confirmed magnesium (Mg) at the surface of the particles be uniformly distributed with phosphorus
Distribution on grain surface.By using CuK α powder to be carried out x-ray diffractogram of powder case measurement, except being equivalent to have stratiform
The LiCoO of rock salt structure2Diffraction maximum outside, have also demonstrated and be equivalent to Li3PO4Diffraction maximum.Additionally, the concentration of magnesium is by cutting
Open the cross section of lithium-compound transition metal oxide, and confirmed by auger electron spectrometry Elemental redistribution radially.Surveying
After Elemental redistribution in the cross section of amount lithium-compound transition metal oxide, the concentration of magnesium is proved to be from the surface of granule inside
Portion's consecutive variations.
By use lithium-compound transition metal oxide obtained as described above as positive active material, according to embodiment
Method identical in 1-1 has manufactured rechargeable nonaqueous electrolytic battery.
Battery is carried out initial capacity, capability retention and the evaluation of High temperature storage performance.High temperature dwell sustainability identified below
Energy.
In the environment of the environment temperature of 45 DEG C, battery manufactured as above is charged with the charging current of 1.5A until
4.35V charging voltage.With the discharge current of 2.0A, battery is discharged the most immediately, and when cell voltage is reduced to
Electric discharge is terminated during 3.0V.Then by battery being carried out High temperature storage in 300 hours in the environment of being retained in the environment temperature of 60 DEG C.
Afterwards, by measuring the discharge capacity after High temperature storage with 0.2C electric discharge.Electric discharge after utilizing initial capacity and insulation to preserve
Capacity, obtains high temperature capability retention according to the following formula, i.e. high temperature dwell sustainability.High temperature capability retention [%]=(insulation preserves
After discharge capacity/initial capacity) × 100.
<embodiment 3-2>
In the way of identical with embodiment 3-1, prepare rechargeable nonaqueous electrolytic battery, and with phase in embodiment 3-1
Same mode carries out initial capacity, capability retention and High temperature storage and keeps the evaluation of performance, and difference is, charging voltage
For 4.2V.
<embodiment 3-3>
In the way of identical with embodiment 3-1, prepare rechargeable nonaqueous electrolytic battery, and with phase in embodiment 3-1
Same mode carries out initial capacity, capability retention and High temperature storage and keeps the evaluation of performance, and difference is, charging voltage
For 4.5V.
<embodiment 3-4>
Preparing positive active material in the way of identical with embodiment 3-1, difference is, the second temperature burnt till
Degree is set to 950 DEG C, and the second time burnt till was 30 minutes.At ratio d=0.02%, molar fraction ratio under 0.05%
Rate r is respectively 0.22,0.21.It is respectively 0.38,0.16 in ratio d=0.01%, molar fraction ratio r under 0.10%.With
The mode identical with embodiment 3-1 prepares rechargeable nonaqueous electrolytic battery, and enters in the way of identical with embodiment 3-1
Row initial capacity, capability retention and High temperature storage keep the evaluation of performance, and difference is, charging voltage is 4.5V.
<embodiment 3-5>
Preparing positive active material in the way of identical with embodiment 3-1, difference is, answering as base material
Conjunction oxide is LiCo0.95Al0.01Mg0.04O2.It is respectively in ratio d=0.02%, molar fraction ratio r under 0.05%
0.73、0.52.It is respectively 0.86,0.44 in ratio d=0.01%, molar fraction ratio r under 0.10%.With with embodiment 3-
Mode identical in 1 prepares rechargeable nonaqueous electrolytic battery, and initially holds in the way of identical with embodiment 3-1
Amount, capability retention and High temperature storage keep the evaluation of performance.
<embodiment 3-6>
Preparing positive active material in the way of identical with embodiment 3-1, difference is, answering as base material
Conjunction oxide is LiCo0.97Al0.01Mg0.02O2.It is respectively in ratio d=0.02%, molar fraction ratio r under 0.05%
0.31、0.31.It is respectively 0.56,0.25 in ratio d=0.01%, molar fraction ratio r under 0.10%.With with embodiment 3-
Mode identical in 1 prepares rechargeable nonaqueous electrolytic battery, and initially holds in the way of identical with embodiment 3-1
Amount, capability retention and High temperature storage keep the evaluation of performance.
<embodiment 3-7>
Preparing positive active material in the way of identical with embodiment 3-1, difference is, answering as base material
Conjunction oxide is LiCoO3And with lithium carbonate Li2CO3, magnesium carbonate MgCO3, ammonium dihydrogen phosphate NH4H2PO4Shown in table 3 and table 4
Ratio mixing.It is respectively 0.46,0.40 in ratio d=0.02%, molar fraction ratio r under 0.05%.At ratio d=
0.01%, the molar fraction ratio r under 0.10% is respectively 0.55,0.44.Prepare in the way of identical with embodiment 3-1
Rechargeable nonaqueous electrolytic battery, and carry out initial capacity, capability retention and high temperature dwell in the way of identical with embodiment 3-1
Deposit the evaluation keeping performance.
<embodiment 3-8>
Preparing positive active material in the way of identical with embodiment 3-1, difference is, uses LiCoO2Make
For the lithium-cobalt composite oxide for base material, and coat with the coating material of nickel hydroxide and manganese phosphate.In coating, system
Standby and mix material and make to be respectively in ratio d=0.02%, molar fraction ratio r (Ni+Mn/Ni+Mn+Co) under 0.05%
0.35,0.34, and it is respectively 0.56,0.25 in ratio d=0.01%, molar fraction ratio r under 0.10%.With with enforcement
Mode identical in example 3-1 prepares rechargeable nonaqueous electrolytic battery, and carries out initial in the way of identical with embodiment 3-1
Capacity, capability retention and the evaluation of High temperature storage characteristic.
<comparative example 3-1>
Use does not has cated composite oxides LiCo0.98Al0.01Mg0.01O2As positive active material.At ratio d=
0.02%, the molar fraction ratio r under 0.05% is respectively 0.01,0.01.Ratio d=0.01%, under 0.10% mole
Fractional ratio r is respectively 0.01,0.01.Rechargeable nonaqueous electrolytic battery is prepared in the way of identical with embodiment 3-1, and
Initial capacity, capability retention and the evaluation of High temperature storage characteristic is carried out in the way of identical with embodiment 3-1.
<comparative example 3-2>
Preparing positive active material in the way of identical with embodiment 3-1, difference is, LiCoO2For making
For the lithium-cobalt composite oxide of base material, and with lithium carbonate Li2CO3, magnesium carbonate MgCO3With ammonium dihydrogen phosphate NH4H2PO4With Co:
The molar ratio mixing of Li:Mg:P=100:1:0.5:1.Divide in ratio d=0.02%, molar fraction ratio r under 0.05%
It is not 0.18,0.10.It is respectively 0.25,0.08 in ratio d=0.01%, molar fraction ratio r under 0.10%.With with enforcement
Mode identical in example 3-1 prepares rechargeable nonaqueous electrolytic battery, and carries out initial in the way of identical with embodiment 3-1
Capacity, capability retention and the evaluation of High temperature storage characteristic.
<comparative example 3-3>
Preparing positive active material in the way of identical with embodiment 3-1, difference is, lithium-cobalt composite oxygen
Compound LiCo0.98Al0.01Mg0.01O2, lithium carbonate Li2CO3, magnesium carbonate MgCO3With ammonium dihydrogen phosphate NH4H2PO4With Co:Li:Mg:P
The molar ratio mixing of=100:1:1:4.Be respectively 0.82 in ratio d=0.02%, molar fraction ratio r under 0.05%,
0.83.It is respectively 0.80,0.85 in ratio d=0.01%, molar fraction ratio r under 0.10%.With with phase in embodiment 3-1
Same mode prepares rechargeable nonaqueous electrolytic battery, and carries out initial capacity, capacity in the way of identical with embodiment 3-1
Conservation rate and the evaluation of High temperature storage characteristic.
<comparative example 3-4>
Preparing positive active material in the way of identical with embodiment 3-1, difference is, the second temperature burnt till
Degree is set to 950 DEG C, and the second time burnt till was 30 minutes.At ratio d=0.02%, molar fraction ratio under 0.05%
Rate r is respectively 0.22,0.21.It is respectively 0.38,0.16 in ratio d=0.01%, molar fraction ratio r under 0.10%.With
The mode identical with embodiment 3-1 prepares rechargeable nonaqueous electrolytic battery, and enters in the way of identical with embodiment 3-1
Row initial capacity, capability retention and the evaluation of High temperature storage characteristic.
<comparative example 3-5>
Preparing positive active material in the way of identical with embodiment 3-1, difference is,
LiCo0.95Al0.01Mg0.04O2For the lithium-cobalt composite oxide as base material.Ratio d=0.02%, rubbing under 0.05%
You are respectively 0.73,0.52 at fractional ratio r.Be respectively 0.86 in ratio d=0.01%, molar fraction ratio r under 0.10%,
0.44.Rechargeable nonaqueous electrolytic battery is prepared in the way of identical with embodiment 3-1, and with identical with embodiment 3-1
Mode carry out initial capacity, capability retention and the evaluation of High temperature storage characteristic.
<comparative example 3-6>
Rechargeable nonaqueous electrolytic battery is manufactured in the way of identical with comparative example 3-5.With identical with embodiment 3-1
Mode battery is carried out initial capacity, capability retention and the evaluation of High temperature storage characteristic, difference is, during charging
Cell voltage is 4.2V.
<comparative example 3-7>
Rechargeable nonaqueous electrolytic battery is manufactured in the way of identical with comparative example 3-5.With identical with embodiment 3-1
Mode battery is carried out initial capacity, capability retention and the evaluation of High temperature storage characteristic, difference is, during charging
Cell voltage is 4.5V.
<comparative example 3-8>
Preparing positive active material in the way of identical with embodiment 3-1, difference is, omits second and burns till
Step.It is respectively 0.80,0.81 in ratio d=0.02%, molar fraction ratio r under 0.05%.Ratio d=0.01%,
Molar fraction ratio r under 0.10% is respectively 0.82,0.79.Non-water power is manufactured in the way of identical with embodiment 3-1
Solve electrolitc secondary cell, and carry out initial capacity, capability retention and High temperature storage characteristic in the way of identical with embodiment 3-1
Evaluation.
<comparative example 3-9>
Preparing positive active material in the way of identical with embodiment 3-1, difference is, carries out mechanochemistry
Process 15 minutes.It is respectively 0.21,0.16 in ratio d=0.02%, molar fraction ratio r under 0.05%.At ratio d=
0.01%, the molar fraction ratio r under 0.10% is respectively 0.31,0.14.Manufacture in the way of identical with embodiment 3-1
Rechargeable nonaqueous electrolytic battery, and carry out initial capacity, capability retention and high temperature dwell in the way of identical with embodiment 3-1
Deposit the evaluation of characteristic.
<comparative example 3-10>
Preparing positive active material in the way of identical with embodiment 3-1, difference is, LiCoO2With effect
In the lithium-cobalt composite oxide of base material, and coat with the coating material of nickel hydroxide and manganese phosphate.In coating, preparation is also
Mixing material makes the molar ratio=1:1:1 of the Ni:Co:Mn in whole positive active material granule, and at ratio d=
0.02%, the molar fraction ratio r (Ni+Mn/Ni+Mn+Co) under 0.05% is respectively 0.25,0.17, and at ratio d=
0.01%, the molar fraction ratio r under 0.10% is respectively 0.30,0.15.Manufacture in the way of identical with embodiment 3-1
Rechargeable nonaqueous electrolytic battery, and carry out initial capacity, capability retention and high temperature dwell in the way of identical with embodiment 3-1
Deposit the evaluation of characteristic.
The positive active material of the rechargeable nonaqueous electrolytic battery of embodiment 3-1 to 3-8 and comparative example 3-1 to 3-10
Structure and evaluation result are shown in Table 3 below and table 4.
From evaluation result it can be seen that can realize good by the decline of control initial capacity among embodiment 3-1 to 3-8
Good capability retention and High temperature storage characteristic.On the other hand, in comparative example 3-1 to 3-10, there is no these effects.
The ratio d of the positive active material of embodiment 3-1 to 3-8 meets the molar fraction under 0.02%≤d≤0.05%
Ratio r falls in scope 0.20≤r≤0.80.Further, they present the model meeting 0.02%≤d≤0.05% at ratio d
In enclosing, the trend that molar ratio r reduces from surface to depth direction.
When the ratio d (%) of certain depth scope (i.e. from a surface to 10nm to 100nm) meets 0.02%≤d≤0.05%
Time, comparative example 3-1 to 3-2,3-4, the molar fraction ratio r of positive active material of 3-9 to 3-10 are constants or along the degree of depth
Direction reduces.But molar fraction ratio r does not fall in the scope of 0.20≤r≤0.80.
The molar fraction ratio r of comparative example 3-1, not in the scope of 0.20≤r≤0.80, is because not using coating
Material.The molar fraction ratio r of comparative example 3-2, not in the scope of 0.20≤r≤0.80, is because base material and coating material
Mixed volume is not suitable.The molar fraction ratio r of comparative example 3-4, not in the scope of 0.20≤r≤0.80, is because
Two firing temperatures are 750 DEG C.The molar fraction ratio r of comparative example 3-9, not in the scope of 0.20≤r≤0.80, is because machine
The tool chemically treated time is 15 minutes, and it is the shortest compared with embodiment 3-1.The molar fraction ratio r of comparative example 3-10 does not exists
In the scope of 0.20≤r≤0.80, the mixed volume being because base material and coating material is not suitable.
Ratio d (%) meet 0.02%≤d≤0.05% time, the positive active material of comparative example 3-3 and 3-8 mole
Fractional ratio r falls outside the scope of 0.20≤r≤0.80.And they demonstrate such trend: in certain depth scope (i.e.
10nm to 100nm from surface) meet in the range of 0.02%≤d≤0.05% at ratio d (%), molar ratio r is from table
Face increases to depth direction.
The molar fraction ratio r of the positive active material of comparative example 3-3 falls outside the scope of 0.20≤r≤0.80, be because of
Mixed volume for base material and coating material is not suitable.The molar fraction ratio r of the positive active material of comparative example 3-8 falls
Outside the scope of 0.20≤r≤0.80, it is because not carrying out second and burns till process.
The molar fraction ratio r of the positive active material of comparative example 3-5 to 3-7 falls in the range of 0.20≤r≤0.80.
But they present such trend: when full at ratio d (%) in certain depth scope (i.e. from a surface to 10nm to 100nm)
In the range of foot 0.02%≤d≤0.05%, molar fraction ratio r increases from surface to depth direction.
The molar fraction ratio r of the positive active material of comparative example 3-5 to 3-7 increases, and is because second and burns till process
Temperature is 850 DEG C.
As implied above go out, at the model meeting 0.02%≤d≤0.05% from surface to certain depth scope at ratio d
In enclosing, when molar fraction ratio r falls in the range of 0.20≤r≤0.80, can be realized by the decline of suppression initial capacity
Good capability retention and High temperature storage characteristic.
About the preparation method of positive active material, as embodiment 3-1 to 3-6, metallic element M2 is preferably from base
Material causes surface.Preparation method makes technique simple, and the material prepared has a distribution evenly in surface, and very
Keep structure well, which improve capability retention and High temperature storage characteristic.
Evaluation result from table 4 is it can be seen that have the positive pole at 0.02%≤d≤0.05% extraneous ratio d
Active substance differs and improves capability retention and High temperature storage characteristic surely, even if molar fraction ratio r is in 0.20≤r≤0.80
In the range of.
About the analysis method on the surface of positive active material, be used for so far XPS (x-ray photoelectron power spectrum) and
TOF-SIMS (time of flight secondary ion massspectrometry).Table 3 shows the molar fraction ratio r of measurement, wherein by these methods
The ratio d corresponding with the depth bounds along depth direction measured is 0.010%, and it is corresponding to the district of a few nm degree of depth from surface
Territory, and wherein measured by the method is 0.100% corresponding to the ratio d of depth bounds along depth direction, and it is corresponding
In from the region more than the 100nm degree of depth on surface.
<embodiment 3-9>
Take the rechargeable nonaqueous electrolytic battery as manufactured in embodiment 3-4 apart, and from electrode, peel positive electrode collector off,
From positive active material, remove binding agent by being immersed in NMP, burn conductive agent to obtain positive active material.At ratio
Molar fraction ratio r under d=0.02% and 0.05% is respectively 0.29 and 0.22.
<embodiment 3-10>
Take the rechargeable nonaqueous electrolytic battery as manufactured in embodiment 3-5 apart, and from electrode, peel positive electrode collector off,
From positive active material, remove binding agent by being immersed in NMP, burn conductive agent to obtain positive active material.At ratio
Molar fraction ratio r under d=0.02% and 0.05% is respectively 0.79 and 0.53.
Structure and the evaluation result of the positive active material of the rechargeable nonaqueous electrolytic battery of embodiment 3-9 and 3-10 are shown in
In table 5 below.
Table 5
Annotation:
U.: uniformly, nu.: uneven, pr.: exist, ab.: do not exist, int.: spread
Table 5 shows when removing positive active material from rechargeable nonaqueous electrolytic battery, ratio d 0.02% to
Molar fraction ratio r under 0.05% falls 0.20, and < r is < in the range of 0.80.
<embodiment 3-11>
Prepare positive active material as follows.
With the atom ratio of Co:P=99:1 mix with embodiment 3-1 identical have measured by laser scattering method
The lithium of 13 μm average diameters-cobalt/cobalt oxide LiCo0.98Al0.01Mg0.01O26 μm average diameters are become (to pass through with by jet mill comminution
Laser scattering method measure) ammonium dihydrogen phosphate NH4H2PO4。
Mixture is processed 1 hour, with sedimentary phosphor acid dihydride on the surface of lithium-cobalt/cobalt oxide by mechanochemistry device
Ammonium, thus obtain the precursor before firing.With the speed of 3 DEG C/min, this precursor is heated up, and holding 3 is little at 900 DEG C
Time, then Slow cooling, to obtain lithium-compound transition metal oxide.This lithium-compound transition metal oxide has equably
The magnesium (Mg) being distributed on the surface of lithium-compound transition metal oxide granule.Additionally, the concentration of magnesium (Mg) is at particle surface ratio
Height, and lithium phosphate (Li is wanted in the inside of granule3PO4) spread at the surface of the particles.
Incidentally, the surface concentration gradient of magnesium Mg is confirmed in detail.Ratio d=0.01%, 0.015%,
0.02%, the molar fraction ratio r at 0.05% is respectively 0.82,0.73,0.62 and 0.40.
The apparent condition of the material obtained confirms by observing the powder of acquisition under SEM/EDX.When observing, it was demonstrated that
Magnesium (Mg) being uniformly distributed and phosphorus distribution at the surface of the particles at the surface of the particles.By using CuK α that granule is carried out powder
The measurement of end X-ray diffraction pattern, except being equivalent to the LiCoO with layered rock salt structure2Diffraction maximum outside, have also demonstrated
Be equivalent to Li3PO4Diffraction maximum.Additionally, the concentration of magnesium is by cutting the cross section of lithium-compound transition metal oxide, and pass through Russia
Auger electron spectroscopy is measured Elemental redistribution radially and is confirmed.Measure granule cross section in Elemental redistribution time, the concentration quilt of magnesium
Turn out to be from the surface of granule towards internal consecutive variations.
By use lithium-compound transition metal oxide granule obtained as described above as positive active material, with enforcement
Mode identical in example 3-1 has manufactured rechargeable nonaqueous electrolytic battery, and to battery in the way of identical with embodiment 3-1
Initial capacity, capability retention and the evaluation of High temperature storage characteristic are carried out.
<embodiment 3-12>
Preparing positive active material in the way of identical with embodiment 3-11, difference is, with Co:P=
The atom ratio mixing of 98.8:1.2 has the lithium-cobalt/cobalt oxide of the 6 μm average diameters measured by laser scattering method
LiCo0.98Al0.01Mg0.01O2The biphosphate of 6 μm average diameters (being measured by laser scattering method) is become with by jet mill comminution
Ammonium NH4H2PO4。
Incidentally, the surface concentration gradient of magnesium Mg is confirmed in detail.Ratio d=0.01%, 0.015%,
0.02%, the molar fraction ratio r at 0.05% is respectively 0.92,0.85,0.80 and 0.65.
By use lithium-compound transition metal oxide granule obtained as described above as positive active material, with enforcement
Mode identical in example 1-1 has manufactured rechargeable nonaqueous electrolytic battery.And to electricity in the way of identical with embodiment 3-11
Pond has carried out initial capacity, capability retention and the evaluation of High temperature storage characteristic.
<embodiment 3-13>
Lithium-the cobalt with 6 μm average diameters (being measured by laser scattering method) is mixed with the atom ratio of Co:S=99:1
Oxide LiCo0.98Al0.01Mg0.01O2The sulfur of 3 μm average diameters (being measured by laser scattering method) is become with by jet mill comminution
Acid ammonium (NH4)2SO4.Mixture is processed 30 minutes, so that ammonium sulfate precipitation is at the table of lithium-cobalt/cobalt oxide by planetary-type mixer
On face.In addition to said process, in the way of identical with embodiment 3-11, prepare positive active material.At ratio d=
0.01%, the molar fraction ratio r at 0.015%, 0.02%, 0.05% is respectively 0.80,0.71,0.58 and 0.38.
By use lithium-compound transition metal oxide granule obtained as described above as positive active material, with enforcement
Mode identical in example 3-11 has manufactured rechargeable nonaqueous electrolytic battery.And to electricity in the way of identical with embodiment 3-11
Pond has carried out initial capacity, capability retention and the evaluation of High temperature storage characteristic.
<embodiment 3-14>
Preparing positive active material in the way of identical with embodiment 3-11, difference is, with Co:P=99:
The atom ratio mixed phosphate ammonium dihydrogen NH of 14H2PO4With the lithium cobalt with the 100 μm average diameters measured by laser scattering method
Oxide.
Incidentally, the surface concentration gradient of magnesium Mg is confirmed in detail.Ratio d=0.01%, 0.015%,
0.02%, the molar fraction ratio r at 0.05% is respectively 0.62,0.53,0.44 and 0.25.
By use lithium-compound transition metal oxide granule obtained as described above as positive active material, with enforcement
Mode identical in example 3-11 has manufactured rechargeable nonaqueous electrolytic battery.And to electricity in the way of identical with embodiment 3-11
Pond has carried out initial capacity, capability retention and the evaluation of High temperature storage characteristic.
<comparative example 3-11>
Preparing positive active material in the way of identical with embodiment 3-11, difference is, with Co:P=95:
The atom ratio mixed phosphate ammonium dihydrogen NH of 54H2PO4With the lithium cobalt oxide with the 6 μm average diameters measured by laser scattering method
Compound.
Incidentally, the surface concentration gradient of magnesium Mg is confirmed in detail.Ratio d=0.01%, 0.015%,
0.02%, the molar fraction ratio r at 0.05% is respectively 0.98,0.95,0.92 and 0.85.
By use lithium-compound transition metal oxide granule obtained as described above as positive active material, with enforcement
Mode identical in example 3-11 has manufactured rechargeable nonaqueous electrolytic battery.And to electricity in the way of identical with embodiment 3-11
Pond has carried out initial capacity, capability retention and the evaluation of High temperature storage characteristic.
<comparative example 3-12>
Preparing positive active material in the way of identical with embodiment 3-11, difference is, with Co:S=99:
The atom ratio mixing ammonium sulfate (NH of 14)2SO4With the lithium cobalt oxidation with the 6 μm average diameters measured by laser scattering method
Thing.
Incidentally, the surface concentration gradient of magnesium Mg is confirmed in detail.Ratio d=0.01%, 0.015%,
0.02%, the molar fraction ratio r at 0.05% is respectively 0.33,0.25,0.20 and 0.15.
By use lithium-compound transition metal oxide granule obtained as described above as positive active material, with enforcement
Mode identical in example 3-11 has manufactured rechargeable nonaqueous electrolytic battery.And to electricity in the way of identical with embodiment 3-11
Pond has carried out initial capacity, capability retention and the evaluation of High temperature storage characteristic.
Embodiment 3-11 to 3-14, the positive active material of rechargeable nonaqueous electrolytic battery of comparative example 3-11 to 3-12
Structure and evaluation result are shown in table 6 below.
From the evaluation result shown in table 6 it can be seen that meet in the range of 0.02%≤d≤0.05% at ratio d, implement
Example 3-11, the molar fraction ratio r of positive active material of 3-12,3-13 fall in scope 0.20≤r≤0.80.And with
Time, < in the range of 0.02%, molar fraction ratio r falls at scope 0.55≤r < in 1.0 to meet 0.01%≤d at ratio d.Logical
Crossing the decline of the discharge capacity suppressing them, these embodiments show the biggest holding capacity rate of improvement and High temperature storage is special
Property.
Meet in the range of 0.02%≤d≤0.05% at ratio d, the positive active material of embodiment 3-14 mole point
Percentage r falls in scope 0.20≤r≤0.80.But ratio d meet 0.01%≤d < in the range of 0.02%, mole point
Percentage r does not fall at scope 0.55≤r < in 1.0.Embodiment 3-14 can not obtain holding capacity or the high temperature dwell that height improves
Sustainability.Because the average diameter of coating material ammonium dihydrogen phosphate is 100 μm, this upsets the good admixture of ammonium dihydrogen phosphate,
Thus good coating state can not be obtained on the surface of base material.
Ratio d meet 0.01%≤d < in the range of 0.02%, the positive active material of comparative example 3-11 mole point
Percentage r falls at scope 0.55≤r < in 1.0.But meet in the range of 0.02%≤d≤0.05% at ratio d, mole point
Percentage r falls outside scope 0.20≤r≤0.80.This is because too many coating material makes coating the thickest, its minimizing helps
Positive active material in charge-discharge capacities.Therefore, the initial discharge capacity of comparative example 3-11 is the least.
Ratio d meet 0.01%≤d < in the range of 0.02%, the positive active material of comparative example 3-12 mole point
Percentage r falls at scope 0.55≤r < outside 1.0.This is because coating material mixes with base material the most well and can not obtain
Good coating.Therefore, the good improvement of holding capacity and High temperature storage characteristic can not be obtained by comparative example 3-12.
It will be understood by those within the art that, can according to design require and other factors carry out various change,
Combination, sub-portfolio and change, as long as they are in the range of claims or its equivalent.