CN108598422A - Electrode, nonaqueous electrolyte battery, battery pack and vehicle - Google Patents

Abstract

According to an embodiment, nonaqueous electrolyte battery includes positive (3), cathode (4) and nonaqueous electrolyte.Positive (3) include by LiFe_1‑xMn_xSO₄What F was indicated has the compound of at least one crystal structure selected from water phosphorus lithium iron-stone and triplite, wherein 0≤x≤0.2.Cathode (4) includes titanium-containing oxide.

Description

Electrode, nonaqueous electrolyte battery, battery pack and vehicle

The application be submit on January 31st, 2013 application No. is 201310038915.7, entitled " nonaqueous electrolyte electricities The divisional application of the application of pond and battery pack ".

Cross reference to related applications

The application is and to ask to enjoy based on the 2012-074801 Japanese patent applications submitted on March 28th, 2012 Its priority, the entire contents are incorporated herein by reference.

Technical field

In general, embodiment described herein is related to nonaqueous electrolyte battery and battery pack.

Background technology

Lithium ion battery including anode and cathode is widely used as the power supply of driving mobile device, and the anode contains The metal oxide of lithium, such as LiCoO₂Or LiMn₂O₄, the cathode includes carbonaceous material, absorbs and discharge lithium ion.However, There is storage characteristics, floating charging patience, cycle life in a high temperauture environment for the battery request of automobile or accumulating system Energy, high-output power, safety, long-term reliability etc..For this purpose, the material for constituting anode and cathode in lithium ion battery It is necessary to have the materials of excellent chemical stability and electrochemical stability for material.Someone has studied LiFePO₄As positive material Material.However, in the case, the penalty under high temperature durability and low temperature environment becomes project.For vehicular applications, also want The high-performance in cold district is sought, such as requires under low temperature environment the high output performance and cycle life performance of (such as -40 DEG C). On the other hand, although lead accumulator (12V) is widely used for the battery in automobile starter and accumulating system for a long time, Someone, which has studied, substitutes lead accumulator to reduce battery weight and realize unleaded.It is stored however, still cannot achieve and substitute lead The battery of battery.

Therefore, the electricity instead of lead accumulator for being mounted in automobile (vehicular applications) or accumulating system (fixed to use) Pond, there are projects in terms of high temperature durability, floating charging patience and low temperature output performance.It is difficult to existing battery substituting lead storage Battery is mounted on as starter power supply in the engine chamber of automobile.

Invention content

The embodiment is designed to provide the non-aqueous solution electrolysis with excellent floating charging patience and low temperature output performance Electrolyte cell.

According to an embodiment, nonaqueous electrolyte battery includes anode, cathode and nonaqueous electrolyte.Anode comprising by LiFe_1-xMn_xSO₄What F was indicated has at least one crystal structure for being selected from water phosphorus lithium iron-stone (tavoraite) and triplite Compound, wherein 0≤x≤0.2.Cathode includes titanium-containing oxide.

According to the embodiment, the nonaqueous electrolyte with excellent floating charging patience and low temperature output performance can be provided Battery.

Description of the drawings

Fig. 1 is the part hollow out sectional view for the nonaqueous electrolyte battery for showing embodiment；

Fig. 2 is the side view for showing the battery in Fig. 1；

Fig. 3 is the perspective view of an embodiment of the battery module for showing the battery pack for embodiment；

Fig. 4 be show embodiment 1 battery and Comparative Examples 1 and 2 and 5 battery depth of discharge and cell voltage between The figure of relationship；

Fig. 5 is relationship between the depth of discharge for showing Examples 1 and 2 and comparative example 2, positive electrode potential and negative potential Figure.

Specific implementation mode

According to an embodiment, nonaqueous electrolyte battery includes anode, cathode and nonaqueous electrolyte.Anode comprising by LiFe_1-xMn_xSO₄What F was indicated has the compound of at least one crystal structure selected from water phosphorus lithium iron-stone and triplite, In 0≤x≤0.2.Cathode includes titanium-containing oxide.

Explain embodiment with reference to the accompanying drawings.

First embodiment

According to the first embodiment, nonaqueous electrolyte battery is provided, it includes anode, cathode and nonaqueous electrolytes.Cathode Including titanium-containing oxide.The charged electric potential curve and discharge potential curve that such cathode has flatness high, but charge and put Potential is in its respective final stage suddenly change.If for this purpose, the only oxide such as LiFePO with olivine structural₄It is used as Positive electrode active materials, then similar with cathode, the charging and discharging potential of the anode of gained changes suddenly in its respective final stage Become.It therefore, also can be prominent in the final stage of charging and the final stage of electric discharge using the voltage of such anode and the battery of cathode So variation, so being difficult to change measurement capacity, SOC (charged state), SOD (discharge condition) or depth of discharge by cell voltage (DOD).Anode in the embodiment includes by LiFe_1-xMn_xSO₄What F was indicated has at least one brilliant selected from water phosphorus lithium iron-stone The compound (hereinafter referred to as ithium iron manganese compound) of the crystal structure of body structure and triplite crystal structure, wherein 0≤x≤ 0.2, positive electrode potential gradually changes respectively in the final stage of charging and the final stage of electric discharge.When the positive electrode and negative electrode combine When, voltage change curve can be to mitigate, therefore be easy to pass through respectively in the final stage of charging and the final stage of electric discharge Cell voltage changes measurement capacity, SOC, SOD or DOD, and can prevent overcharge and overdischarge.

According to the embodiment, can inhibit in hot environment or during floating charging it is anti-between anode and nonaqueous electrolyte It answers, to inhibit the growth of the film generated on positive electrode surface.It is possible thereby to inhibit the increase of the interface resistance on anode, therefore can To improve the life performance in the high temperature charge and discharge cycles when implementing up to 100% floating charging of SOC.Furthermore, it is possible to change Discharge rate performance under low temperature environment (such as -20 DEG C or lower).

The medium voltage of the battery of the embodiment is about 2V, and the numerical value obtained with lead accumulator is almost equal.Therefore, The battery of the embodiment has excellent compatibility with lead accumulator, and uses the battery strings of the wherein 6 pieces embodiments The voltage of 12V may be implemented in the battery pack for joining the battery module of connection, can substitute lead accumulator.When the battery pack replaces lead When accumulator is mounted in the engine chamber of automobile, compared with the case where using lead accumulator, it can obtain with the more long-life Smaller and lighter engine.

In order to improve the output performance under low temperature, the grain size of ithium iron manganese compound is preferably reduced.However, working as ithium iron manganese chemical combination When the grain size of object reduces, the reactivity between nonaqueous electrolyte and moisture becomes larger.When at least one of ithium iron manganese compound particle When surface being divided to be covered by the coating comprising at least one material selected from carbon material, phosphorus compound, fluoride and metal oxide, The reactivity between nonaqueous electrolyte and moisture can be reduced in the case where grain size reduces.Therefore, up to 100% can be inhibited SOC floating charging in nonaqueous electrolyte oxidative decomposition and reacted with moisture in air.When use ithium iron manganese chemical combination When composition granule, this can greatly improve the cycle life performance of battery, therefore can greatly improve (such as -20 DEG C of low temperature environment Or it is lower) under battery discharge rate performance.

Explained later anode, cathode, nonaqueous electrolyte, diaphragm and container.

Anode

The anode has positive electrode collector and positive electrode material layer (layer containing positive electrode active materials), the one of the collector It is formed on side or both sides, and includes positive electrode active materials, conductive materials and adhesive.

Positive electrode active materials include by LiFe_1-xMn_xSO₄What F was indicated has at least one selected from water phosphorus lithium iron-stone crystal knot The compound of the crystal structure of structure and triplite crystal structure (ithium iron manganese compound), wherein 0≤x≤0.2.

When the range of x is more than 0.2, property, floating charging patience and the low temperature output performance of high temperature durability can deteriorate.When When x is in the range of 0≤x≤0.1, water phosphorus lithium iron-stone crystal structure can be readily available.When x is 0.1<The range of x≤0.2 When middle, triplite crystal structure can also be readily available.Ithium iron manganese compound with water phosphorus lithium iron-stone crystal structure It can be by lithium-absorbing potential regulating to 3.55V (relative to Li/Li⁺).Ithium iron manganese chemical combination with triplite crystal structure Object can be by lithium-absorbing potential regulating to 3.85V (relative to Li/Li⁺).By Li_4/3+xTi_5/3O₄What is indicated has spinel structure Li-Ti oxide lithium-absorbing potential be 1.55V (relative to Li/Li⁺), wherein 0≤x≤1.When comprising with spinelle knot It, can when the cathode of the Li-Ti oxide of structure is combined with the anode comprising the ithium iron manganese compound with water phosphorus lithium iron-stone crystal structure To realize the medium voltage of about 2V, therefore the battery with the compatibility excellent with lead accumulator may be implemented.Therefore, work as use When water phosphorus lithium iron-stone crystal structure, may be implemented to have excellent high temperature durability, floating charging patience, low temperature output performance and with The battery of the compatibility of lead accumulator.

Preferably, the average primary particle diameter of the primary granule of ithium iron manganese compound is in 0.05 μm or bigger to 1 μm or smaller In the range of.Its more preferably ranging from 0.01 μm or bigger are to 0.5 μm or smaller.When primary particle diameter is in this range, The diffusion resistance that lithium ion in active material can be reduced, to obtain improved output performance.Ithium iron manganese compound can wrap Containing the secondary granule for wherein assembling primary granule, size is 10 μm or smaller.

Ithium iron manganese compound can be synthesized for example, by following methods.

By FeSO₄·7H₂O and MnSO₄·H₂O is mixed with scheduled stoichiometric ratio, by mixture at 80 DEG C in vacuum Or it is dehydrated under higher to 150 DEG C or lower temperature.Then, LiF is added with scheduled stoichiometric ratio thereto, and will mixing Object is compression molded into bead.Then, bead is carried out in a nitrogen atmosphere at 200 DEG C or higher to the heat of 350 DEG C or lower temperature Reason.The product of acquisition is ground into the particle of predetermined particle diameter under dry atmosphere, thus to obtain ithium iron manganese compound.In the synthesis In method, work as x, the i.e. molar ratio of Mn, when being adjusted to the range of 0≤x≤0.1, water phosphorus lithium iron-stone crystal structure can be obtained.And And when x is adjusted to 0.1<When the range of x≤0.2, triplite crystal structure can be obtained.

It can be closed selected from carbon material, phosphatization comprising at least one at least part surface of ithium iron manganese compound particle The coating of the material of object, fluoride and metallic oxide type covers.Particle can be any of primary granule and secondary granule State.Carbon material may include having the 0.344nm or d of bigger₀₀₂Carbonaceous material.Phosphorus compound may include lithium phosphate (Li₃PO₄), aluminum phosphate (AlPO₄)、SiP₂O₇Deng.Fluoride may include lithium fluoride (LiF), aluminum fluoride (AlF₃), ferric flouride (FeF_x, wherein 2≤x≤3) etc..Metal oxide may include Al₂O₃、ZrO₂、SiO₂、TiO₂Deng.

The shape of coating may include particle, stratiform etc..When the shape of coating is particle, grain size is preferably 0.1 μm Or smaller, more preferable 0.01 μm or smaller.When the shape of coating is stratiform, thickness is preferably 0.1 μm or smaller, more preferably 0.01 μm or smaller.

The amount of coating be preferably based on the amount of ithium iron manganese compound 0.001 weight % or bigger to 3 weight % or smaller. When the amount of coating is 0.001 weight % or bigger, the increase of positive electrode resistance can be inhibited, so as to cause improved output Energy.On the other hand, when the amount of coating is 3 weight % or smaller, the interface between anode and nonaqueous electrolyte can be inhibited The increase of resistance, so as to cause improved output performance.The amount of coating be more preferably 0.01 weight % or bigger to 1 weight % or Smaller.

Positive electrode active materials can include the material other than ithium iron manganese compound.The example of other positive electrode active materials There are various oxides and sulfide, including such as manganese dioxide (MnO₂), iron oxide, copper oxide, nickel oxide, lithium manganese combined oxidation Object, lithium nickel composite oxide (such as Li_xNiO₂), lithium cobalt composite oxide (such as Li_xCoO₂), lithium/nickel/cobalt composite oxide (such as LiNi_1-y-zCo_yM_zO₂, wherein M be at least one element selected from Al, Cr and Fe, 0≤y≤0.5 and 0≤z≤0.1), lithium manganese Cobalt composite oxide (such as LiMn_1-y-zCo_yM_zO₂, wherein M be at least one element selected from Al, Cr and Fe, 0≤y≤0.5 and 0≤z≤0.1), lithium manganese nickel complex chemical compound (such as LiMn_xNi_xM_1-2xO₂, wherein M is at least one selected from Co, Cr, Al and Fe Element, and 1/3≤x≤1/2, such as LiMn_1/3Ni_1/3Co_1/3O₂Or LiMn_1/2Ni_1/2O₂), spinel type lithium manganese nickel it is compound Oxide (Li_xMn_2-yNi_yO₄), the lithium metal phosphorous oxides with olivine structural, ferric sulfate (such as Fe₂(SO₄)₃), vanadium oxide (such as V₂O₅) etc..In addition, it can also include conducting polymer materials such as polyaniline and polypyrrole, disulfide polymer object material, sulphur (S), organic material such as fluorocarbons and inorganic material.When not describing the preferred scope of x, y and z, 0 or bigger to 1 or smaller Range be preferred.Positive electrode active materials can be administered alone or as its mixture of two or more and use.

Conductive materials may include such as acetylene black, carbon black, graphite, carbon fiber.

Adhesive may include polytetrafluoroethylene (PTFE) (PTFE), polyvinylidene fluoride (PVdF), fluorine-containing rubber etc..

The mixed proportion of active material, conductive materials and adhesive is preferably that the ratio of the positive electrode active materials exists in anode In the range of 80 to 95 weight %, the ratios of the conductive materials is in the range of 3 to 19 weight % and the ratio of the adhesive In the range of 1 to 7 weight %.

Anode can be used for example, by positive electrode active materials, conductive materials and adhesive suspend in a suitable solvent The aluminium foil or alloy foil of the suspension coating collector of gained, are dried and suppress.The ratio table of positive electrode in BET methods Area refers to the surface area (exclude current collection body weight) of every g positive electrode material layers, and it is preferably in 0.1m²/ g or bigger are to 2m²/ g or In the range of smaller.

Collector may include aluminium foil, alloy foil etc..The thickness of collector is 20 μm or smaller, more preferable 15 μm or more It is small.

Cathode

The cathode has negative electrode collector and negative electrode material layer, supports in the one or both sides of the collector, and wrap Containing active material, conductive materials and adhesive.

Negative electrode active material includes Li-Ti oxide.Li-Ti oxide may include by Li_4/3+xTi_5/3O₄What is indicated has The Li-Ti oxide of spinel structure, wherein 0≤x≤1；By Li_xTiO₂What is indicated has bronze structures (B) or anatase structured Titanium oxide, (group before charging becomes TiO wherein 0≤x≤1₂)；By Li_xNb_aTiO₇The niobium titanium oxide of expression, wherein 0 ≤ x, more preferable 0≤x≤1 and 1≤a≤4；And the Li with ramsdellite structure_2+xTi₃O₇(0≤x≤1)；Li_{1+ x}Ti₂O₄, wherein 0≤x≤1；Li_1.1+xTi_1.8O₄, wherein 0≤x≤1；Li_1.07+xTi_1.86O₄, wherein 0≤x≤1；Deng.By Li_xTiO₂The preferred peptide oxide of expression includes having anatase structured TiO₂With the TiO with bronze structures₂(B).300 It is also preferred to the low crystalline oxide being heat-treated at a temperature of 600 DEG C.Other than above compound, this can be used Class compound, a part of Ti components wherein in Li-Ti oxide are selected from Nb, Mo, W, P, V, Sn, Cu, Ni and Fe by least one Element substitution.

The average primary particle diameter of the primary granule of negative electrode active material is in 0.001 μm or bigger to 1 μm or smaller range It is interior.The particle of any shape can obtain good property, such as particle or fiber.The fibre diameter of particle is preferably 0.1 μm Or smaller.

The average grain diameter of desired negative electrode active material is 1 μm or smaller, and specific surface area is 3 to 200m²/ g, root Pass through N according to BET methods₂Absorption measures.This can further enhance the affinity of cathode and nonaqueous electrolyte.

The specific surface area (excluding collector) that negative electrode material layer is measured according to BET methods can be adjusted to 3m²/ g or bigger To 50m²/ g or smaller.Specific surface area is more preferably in 5m²/ g or bigger are to 50m²In the range of/g or smaller.

Cathode (excluding collector) is preferably with the porosity in 20 to 50% ranges.This, which can be provided, has and non-water power Solve the high-affinity of matter and highdensity cathode.Porosity is more preferably in the range of 25 to 40%.

Negative electrode collector is preferably formed by aluminium foil or alloy foil.

The thickness of aluminium foil or alloy foil is 20 μm or smaller, more preferable 15 μm or smaller.

The aluminium foil preferably purity with 99.99 weight % or bigger.

Including the aluminium alloy of at least one element selected from magnesium, zinc and silicon is preferred.It is preferable, however, that will such as iron, copper, The content of the transition metal of nickel or chromium is adjusted to 100ppm by weight or smaller.

Conductive materials may include such as acetylene black, carbon black, coke, carbon fiber, graphite, metal compound powders, metal Powder etc., and they can be used alone or are used as its mixture.Preferred conductive materials may include coke, Heat treatment and average grain diameter are 10 μm or smaller at a temperature of 800 DEG C to 2000 DEG C；Graphite；Acetylene black；And TiO, The metal powder of TiC, TiN, Al, Ni, Cu, Fe etc..

Adhesive may include such as polytetrafluoroethylene (PTFE) (PTFE), polyvinylidene fluoride (PVdF), fluorine-containing rubber, acrylic acid Rubber, styrene butadiene ribber, core-shell structure copolymer adhesive etc..

The mixed proportion of active material, conductive materials and adhesive is preferably that the ratio of the negative electrode active material exists in cathode In the range of 80 to 95 weight %, the ratios of the conductive materials is in the range of 1 to 18 weight % and the ratio of the adhesive In the range of 2 to 7 weight %.

Cathode can be prepared for example, by following methods：Negative electrode active material, conductive materials and adhesive are suspended in conjunction In suitable solvent, collector is coated with the suspension of gained, is dried simultaneously hot pressing.

Nonaqueous electrolyte

Nonaqueous electrolyte can include the liquid nonaqueous electrolyte prepared by electrolyte is dissolved in organic solvent；It is gluey Nonaqueous electrolyte, wherein combination organic solvent and polymeric material；And solid-state nonaqueous electrolyte, wherein combination lithium salts electrolyte and Polymeric material.Including the salt of lithium ion (ionic condition) melted at room temperature is also used as nonaqueous electrolyte.Polymeric material can To include such as polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyethylene glycol oxide (PEO).

As liquid nonaqueous electrolyte, preferably organic electrolyte solution and solidification point is -20 DEG C or lower and boiling point For 100 DEG C or higher room temperature molten salt (ionic liquid).

Liquid nonaqueous electrolyte is prepared by the way that electrolyte to be dissolved in 0.5 to 2.5mol/L concentration in organic solvent.

Electrolyte may include such as LiBF₄、LiPF₆、LiAsF₆、LiClO₄、LiCF₃SO₃、LiN(CF₃SO₂)₂、LiN (C₂F₅SO₂)₂、Li(CF₃SO₂)₃C、LiB[(OCO)₂]₂Deng.The type of electrolyte used can be one or two kinds of or more It is a variety of.Including LiPF₆And LiBF₄At least one of electrolyte be preferred.The chemistry of such electrolyte enhancing organic solvent Stability, it is possible to reduce the film resistance on cathode, and cryogenic property and cycle life performance can be significantly improved.

Organic solvent may include cyclic carbonate, such as propene carbonate (PC) and ethylene carbonate (EC)；Linear carbonic acid Ester, such as diethyl carbonate (DEC), dimethyl carbonate (DMC) and methyl ethyl ester (MEC)；Linear ether, such as dimethoxy second Alkane (DME) and diethoxyethane (DEE)；Cyclic ether, as (THF) are He dioxane (DOX) for tetrahydrofuran；Gamma-butyrolacton (GBL), acetonitrile (AN) and sulfolane (SL).These organic solvents can be used alone or be made with the mixture of two or more With.Preferably comprise at least solvent of the one kind selected from propene carbonate (PC), ethylene carbonate (EC) and gamma-butyrolacton (GBL) Organic solvent, because the boiling point of nonaqueous electrolyte is 200 DEG C or therefore higher simultaneously has high thermal stability when in use.When organic Solvent include it is at least one selected from gamma-butyrolacton (GBL), diethoxyethane (DEE) and diethyl carbonate (DEC) and solvent When, lithium salts can be used with high concentration, therefore can enhance the output performance under low temperature environment.It is preferred that by lithium salts with relative to organic The concentration of solvent 1.5 to 2.5mol/L ranges dissolves.The concentration range even can also provide height output work(at low ambient temperatures Rate.

Room temperature molten salt refers to the salt that its at least part shows liquid at room temperature, and room temperature refer to power supply usually can be with It is considered as the temperature range of work.The temperature range that power supply may generally be considered as work is following range, is limited to about 120 thereon DEG C, about 60 DEG C sometimes, and lower limit is about -40 DEG C, about -20 DEG C sometimes.Wherein, -20 DEG C or higher are to 60 DEG C or lower model It is suitable to enclose.Room temperature molten salt (ion fusant) is preferably by lithium ion, organic substance cation and organic substance anion It is formed.In addition, room temperature molten salt is desirably liquid under room temperature or lower temperature.

Organic substance cation includes alkyl imidazolium ion, with skeleton shown in following formula 1 and quaternary ammonium Ion.

Preferred alkyl imidazolium ion may include dialkylimidazolium ion, trialkylimidazolium ion, tetraalkyl Imidazol ion.Preferred dialkylimidazolium may include 1- methyl -3- ethyl imidazol(e) ions (MEI⁺).Preferred three alkane Base imidazol ion may include 1,2- diethyl -3- propyl imidazole ions (DMPI⁺).Preferred tetraalkyl imidazol ion It may include 1,2- diethyl -3,4 (5)-methylimidazole ion.

Preferred quaternary ammonium ion may include tetraalkyl ammonium ion and cycloalkyl ammonium ion.Preferred tetraalkyl ammonium ion can be with Including dimethyl ethyl methoxy ethyl ammonium ion, dimethyl ethyl methoxy ammonium ion, dimethyl ethyl ethyoxyl second Base ammonium ion and thmethylpropyl ammonium ion.

When using alkyl imidazolium ion or quaternary ammonium ion (especially tetraalkyl ammonium ion), fusing point can be adjusted to 100 DEG C or lower, more preferable 20 DEG C or lower, and the reactivity with cathode can be further decreased.

The concentration of lithium ion is preferably 20 moles of % or less, more preferable 1 to 10 mole of %.When concentration is adjusted to above-mentioned model When enclosing, liquid room temperature molten salt is readily available under such as 20 DEG C or lower low temperature.In addition, even if in room Viscosity can also be reduced at warm or lower temperature, so as to cause the ionic conductance of enhancing.

It is preferably at least a kind of to be selected from BF as anion₄ ^–、PF₆ ^–、AsF₆ ^–、ClO₄ ^–、CF₃SO₃ ^–、CF₃COO^–、CH₃COO^–、 CO₃ ^2–、(FSO₂)₂N^–、N(CF₃SO₂)₂ ^–、N(C₂F₅SO₂)₂ ^–(CF₃SO₂)₃C^–Anion.When a plurality of types of anion are total When depositing, it is 20 DEG C or lower room temperature molten salt that can be readily formed fusing point.Preferred anion may include BF₄ ^–、 (FSO₂)₂N^–、CF₃SO₃ ^–、CF₃COO^–、CH₃COO^–、CO₃ ^2–、N(CF₃SO₂)₂ ^–、N(C₂F₅SO₂)₂ ^–(CF₃SO₂)₃C^–.When using this When a little anion, more easily room temperature molten salt can be obtained under 0 DEG C or lower temperature.

Diaphragm

Diaphragm can be between positive electrode and negative electrode.As diaphragm, such as synthetic resin adhesive-bonded fabric, fiber can be used Plain adhesive-bonded fabric or polyolefin porous membrane (for example, polyethylene porous membrane and polypropylene porous film).Preferred diaphragm includes polyene Hydrocarbon perforated membrane and cellulose fibre adhesive-bonded fabric.

The preferred porosity of diaphragm is 50% or smaller.

Preferably, the thickness of diaphragm is 10 to 100 μm, and density is 0.2 to 0.9g/cm³。

When physical property in the above range when, can obtain good between the increase of mechanical strength and the reduction of cell resistance Good balance, and the battery with high-output power and the property for reducing internal short-circuit can be provided.Heat under hot environment Contraction is small, and can obtain good high temperature storage feature.

It is preferable to use the cellulose fibre diaphragms that porosity is 60% bigger.Diaphragm can be that fibre diameter is 10 μm or more The state of small adhesive-bonded fabric, film, paper etc..Particularly, porosity is 60% or the cellulose fibre diaphragm of bigger has to electricity The good impregnability of matter is solved, and high output performance can be revealed in low temperature to high temperature following table.Preferred range is 62% To 80%.In addition, in long-term storage, porosity is 60% or the cellulose fibre diaphragm of bigger is in charged state, floating charging With, not with negative reaction, and can be prevented internal short caused by tree (dendrite) deposition by lithium metal under overcharge Road.Moreover, when fibre diameter is 10 μm or smaller, the affinity with nonaqueous electrolyte is improved, so as to cause the electricity of reduction Pond resistance.Fibre diameter is more preferably 3 μm or smaller.

Container

The container formed by metal or leaf membrane may be used as the container for accommodating anode, cathode and nonaqueous electrolyte.

It is formed by aluminium, aluminium alloy, iron or stainless steel and may be used as canister for the container of rectangular or cylindrical.Hold The desired plate thickness of device is 0.5mm or smaller, more preferable 0.3mm or smaller.

Leaf membrane may include such as multilayer film, the wherein coverings such as aluminium foil resin film.The example packet of resin may include Polymer, such as polypropylene (PP), polyethylene (PE), nylon and polyethylene terephthalate (PET).The thickness of leaf membrane is preferred For 0.2mm or smaller.The preferred purity of aluminium foil is 99.5 weight % or higher.

It is preferred that forming the metal can of aluminium alloy from alloy, the alloy includes at least one member selected from manganese, magnesium, zinc and silicon The purity of element and aluminium is 99.8 weight % or bigger.The intensity of the metal can of aluminium alloy can obviously increase, therefore its wall thickness Degree can reduce.Thus, it is possible to thin and light battery be realized, with high-output power and excellent thermorodiative property.

The rectangular secondary battery of embodiment of the present invention is shown in Fig. 1 and Fig. 2.As shown in Figure 1, electrode group 1 is placed in rectangle circle In column canister 2.Electrode group 1 has following structure, wherein anode 3, cathode 4 and 5 spiral of diaphragm placed between them Winding, to which resulting product has flat shape.Nonaqueous electrolyte (not shown) is placed in electrode group 1.Such as Fig. 2 institutes Show, the multiple portions positioned at the edge of the anode 3 of the edge surface of electrode group 1 are respectively electrically connected to band-like positive wire 6.Moreover, Multiple portions positioned at the edge of the cathode 4 of this edge surface are respectively electrically connected to band-like negative wire 7.Multiple positive wires 6 Tie together in a group, is electrically connected to positive conductive connector 8.Positive extremity is by 8 shape of positive wire 6 and positive conductive connector At.Negative wire 7 ties together in a group, is electrically connected to negative conductive connector 9.Negative end is by negative wire 7 and bears The formation of pole conductive contact 9.Metal sealing plate 10 is fixed to the opening of canister 2 by welding etc..Positive conductive connector 8 and negative Pole conductive contact 9 is hauled out each by the hole provided in sealing plate 10.The inner circumferential surface in each hole is with absolutely in sealing plate 10 The covering of edge component is to avoid short-circuit with caused by the contact of positive conductive connector 8 or negative conductive connector 9.

The type of battery is not limited to rectangular battery, and can prepare various types of batteries, including cylindrical battery, thin The battery etc. of type battery, coin shapes.In addition, the shape of electrode group is not limited to flat shape, and can be formed cylindrical, thin Piece shape etc..

First embodiment explained above includes cathode, and it includes titanium-containing oxides；And anode, it includes by LiFe_1-xMn_xSO₄What F was indicated has at least one crystalline substance selected from water phosphorus lithium iron-stone crystal structure and triplite crystal structure The compound of body structure, wherein 0≤x≤0.2, therefore nonaqueous electrolyte battery can be provided, it is durable with excellent high temperature Property, floating charging patience and low temperature output performance, and with the compatibility with lead accumulator, capacity, SOC, SOD and DOD can Easily to detect.

Second embodiment

The battery pack of second embodiment includes the nonaqueous electrolyte battery of one or more first embodiments.Battery pack It can be with the battery module for including multiple batteries.Battery can be with serial or parallel connection, and particularly preferably (n is 1 or larger to n groups Integer) concatenated 6 batteries.When use is comprising by LiFe_1-xMn_xSO₄What F wherein 0≤x≤0.1 were indicated has water phosphorus lithium iron When the anode of the compound of stone crystal structure and cathode comprising the Li-Ti oxide with spinel structure, can be had There is the battery of the medium voltage of 2V.In the case, if 6 battery of n groups is connected and n values are 1, in concatenated 6 battery The voltage of battery pack becomes 12V, thus significantly improves the compatibility with lead accumulator group.In addition, using above-mentioned anode and cathode The voltage curve of battery there is suitable oblique angle, therefore it is similar with lead accumulator, only can easily be examined by monitoring voltage Survey its capacity, SOC, SOD and DOD.Therefore, in addition wherein battery string number be 6 n times of battery pack in, can subtract Dot know between variation influence, and may battery only be controlled by monitoring voltage.

One embodiment of the battery module for battery pack is shown in Fig. 3.Battery module 21 shown in Fig. 3 has multiple the The rectangular secondary battery 22 of one embodiment₁To 22₅.Secondary cell 22₁The electricity of positive conductive connector 8 be connected to by lead 23 With battery 22₁Adjacent secondary cell 22₂Negative conductive connector 9.In addition, this secondary cell 22₂Positive conductive connector 8 It is electrically connected to and battery 22 by lead 23₂Adjacent secondary cell 22₃Negative conductive connector 9.Secondary cell 22₁To 22₅With This mode is connected.

As the box set for accommodating battery module, the metal can formed by aluminium alloy, iron or stainless steel and modeling can be used Material container.Container is preferably 0.5mm or the plate of bigger with thickness.

The embodiment of battery pack can arbitrarily change according to purposes.Battery pack is preferred for being desired to have under high current Cycle performance battery pack.Particularly, it is preferred for the power supply of digital camera, and is used for mobile applications, such as such as 2 Wheel to 4 wheel hybrid electric vehicles, 2 wheels to 4 take turns electric vehicles or power assist vehicle.It is preferred for mobile applications.

Second embodiment has the nonaqueous electrolyte battery of the first embodiment, therefore following battery may be implemented Group, with excellent high temperature durability, floating charging patience and low temperature output performance, and with compatible with lead accumulator group Property, capacity, SOC (charged state), SOD (discharge condition) or DOD (depth of discharge) can be detected easily.

Embodiment

Embodiment is explained in detail below with reference to attached drawing.

Embodiment 1

By FeSO₄·7H₂O and MnSO₄·H₂O is measured than mixing with predetermined chemical and vacuum takes off at 90 DEG C by mixture After water, the LiF of predetermined chemical metering ratio is added thereto, and mixture is compression molded into bead.Then, by bead in nitrogen atmosphere Under handled 24 hours at 290 DEG C, to obtain LiFe_0.95Mn_0.05SO₄F, with water phosphorus lithium iron-stone crystal structure and just The average grain diameter of grade particles is 0.3 μm.Pass through the crystal of Rietveld methods and the compound of X ray diffracting spectrum identification synthesis Structure.

Utilize the LiFe obtained in following methods_0.95Mn_0.05SO₄F prepares anode.It is 0.005 μm of carbon to make average grain diameter Grain is bound to LiFe with the binding capacity of 0.1 weight %_0.95Mn_0.05SO₄The surface of F particles is (based on 100 weight %'s LiFe_0.95Mn_0.05SO₄F).The powdered graphite of 5 weight % (amount based on anode) (is based on as conductive materials and 5 weight % The amount of anode) PVdF mixed with the positive electrode active materials of acquisition as adhesive, and mixture is scattered in N- methylpyrroles To prepare slurry in alkanone (NMP) solvent.Two surfaces of the alloy foil (purity is 99 weight %) that thickness is 15 μm are used The slurry of acquisition coats, and is dried, and anode is prepared after pressing step, and 43 μm of positive material is respectively with thickness The bed of material and electrode density are 2.2g/cm³.The specific surface area of positive electrode material layer is 5m²/g。

Respectively, it is 0.8 μm by the average primary particle diameter of primary granule and BET specific surface area is 10m²The Li of/g_4/3Ti_{5/ 3}O₄Powder, the powdered graphite that average grain diameter is 6 μm are as conductive materials and PVdF as adhesive with 95:3:2 weight ratio Mixing, and mixture is scattered in N-Methyl pyrrolidone (NMP), and by dispersion ball mill in the rotating speed of 1000rpm and 2 Stirring is to prepare slurry under conditions of the mixing time of hour.By the alloy foil that thickness is 15 μm (purity is 99.3 weight %) It is coated, is dried, and cathode is prepared after hot pressing step with the slurry of acquisition, 59 μm negative is respectively with thickness Pole material layer and electrode density are 2.2g/cm³.The cathode porosity for excluding collector is 35%.The BET ratios of negative electrode material layer Surface area is 5m (per the surface area of g negative electrode material layers)²/g。

The method of particle for measuring positive electrode active materials and negative electrode active material is as follows.

The particle sizing of active material is using Laser diffraction particle size analyzer (Shimadzu SALD-300) by with lower section Method carries out：First, about 0.1g samples, surfactant and 1 are added to 2mL distilled water to beaker；Mixture is sufficiently stirred； Pour the mixture into stirring bath；With the distribution 64 times of 2 seconds interval measurement luminous intensities；And analysis particle size distribution data.

Pass through N under the following conditions₂Absorption measures BET specific surface area.

As sample, the powder activated materials of 1g or 2 × 2cm are used²Two electrodes (positive or negative pole) slice.It uses The BET specific surface area measuring apparatus of Yuasa-Ionics Co., Ltd manufactures, and nitrogen is used as adsorbed gas.

Respectively, anode is covered with regenerated cellulose fibre diaphragm, and thickness is 30 μm, and porosity 65% is average Fibre diameter is 1 μm, and is formed from the slurry as starting material, and cathode is placed on the anode of gained.Positive material The area of the bed of material (Sp) is 0.98 than the ratio (Sp/Sn) of the area of negative electrode material layer (Sn), and the edge of negative electrode material layer It is protruded from the edge of positive electrode material layer.By the positive electrode, the negative electrode and the separator spiral winding, to generate electrode group.At this moment, positive electrode The electrode width of layer (Lp) is 50mm, and the electrode width of negative electrode material layer (Ln) is 51mm, Lp/Ln 0.98.

The electrode group is pressed into flat shape.The electrode group of gained is placed in the container of thin metal tank, it is thick Degree is 0.25mm, and is formed by aluminium alloy (Al purity is 99 weight %).

Respectively, liquid nonaqueous electrolyte (non-aqueous electrolytic solution) will be by that will be used as the 1.5mol/L tetrafluoro boric acids of lithium salts Lithium (LiBF₄) being dissolved in the mixed solvent of the propene carbonate (PC) as organic solvent and gamma-butyrolacton (GBL), (volume ratio is 1:1) in.The boiling point of nonaqueous electrolyte is 220 DEG C.The nonaqueous electrolyte is poured into the electrode group in container, to generate square Shape non-aqueous electrolyte secondary battery, thickness 10mm, width 50mm are highly 90mm, and with described in figure 1 above Structure.

Embodiment 2

By FeSO₄·7H₂O and MnSO₄·H₂O is measured with predetermined chemical than after mixing, by mixture, vacuum takes off at 90 DEG C Water, and the LiF of stoichiometric ratio is added thereto, and mixture is compression molded into bead.Then, by bead under nitrogen atmosphere It is heat-treated 24 hours at 290 DEG C.It is crushed under dry atmosphere in the product of acquisition, to obtain LiFe_0.85Mn_0.15SO₄F, tool There is triplite crystal structure, and the average primary particle diameter of primary granule is 0.3 μm.It is demonstrate,proved in such a way that embodiment 1 is identical The crystal structure of the compound synthesized in fact.

It is 0.005 μm of Li to make average grain diameter₃PO₄Particle is with 0.1 weight % (based on 100 weight %'s LiFe_0.85Mn_0.15SO₄F binding capacity) is bound to the LiFe of acquisition_0.85Mn_0.15SO₄The surface of F particles.Nonaqueous electrolyte is secondary Battery is prepared in such a way that embodiment 1 is identical, the positive electrode active materials in addition to using acquisition.

Embodiment 3 to 10 and comparative example 1 to 4

Described in the example 1 above it is identical in a manner of prepare rectangular secondary battery, in addition to using shown in following table 1 just Pole active material, negative electrode active material and nonaqueous electrolyte.

Comparative example 5

In comparative example 5, use commercially available lead accumulator (nominal capacity 3.4Ah, 12V, 1.2kg).

At 25 DEG C, with 1C constant-current charges to 2.4V and with 2.4V constant-voltage charges (charging time is 3 hour), then will When it is discharged to 1.5V with 1C, the discharge capacity of each secondary cell obtained in embodiment 1 to 10 and comparative example 2 is measured in Between voltage (cell voltage).

In comparative example 1,3 and 4, at 25 DEG C, with 1C constant-current charges to 4.2V and with 4.2V constant-voltage charges (when charging Between be 3 hours), when it being then discharged to 3.0V with 1C, measure the discharge capacity and medium voltage (cell voltage) of battery.

In embodiment 1 to 10 and comparative example 1 to 4, by preparing in wherein serial embodiment 1 to 10 and comparative example 1 to 4 The battery modules of 6,5 or 3 batteries each obtained obtains battery pack.The number of secondary cell series is set as in battery pack Do not generated in the charge complete voltage of 14.4V overcharge (more than 100% charging) secondary cell number, with have with The compatibility of the charge complete voltage (14.4V) of 12V lead accumulators.

By by battery pack with 1C constant-current charges to 14.4V, with 14.4V constant-voltage charges (charging time is 3 hour), and with 1C is discharged to 50%SOD (discharge condition) to measure the embodiment 1 to 10 obtained under 50%SOD (discharge condition) and comparative example 1 The voltage of the battery pack each to 4.As a result it is shown in table 2.

In high-temperature floating-charge electrical testing, under 60 DEG C of environment, by the battery of each of embodiment 1 to 10 and comparative example 2 and 5 It is electric (100%SOC) with 2.25V constant voltage floating charges, and by the battery of each of comparative example 1,3 and 4 with 4.2V constant-voltage charges (100% SOC), its battery capacity is then measured weekly with 1C electric discharges at 25 DEG C, and capacity maintenance rate reaches to 80% time to determine Justice is viability.

In cryogenic property test, under -30 DEG C of environment, discharge capacity is measured when battery 10C is discharged.It is obtained from above Discharge capacity obtain capacity maintenance rate, the discharge capacity obtained in 1C discharge tests at 25 DEG C is assumed to 100%.

These measurement results are shown in table 2.FeF as the coating in embodiment 5_xMeet the range of 1≤x≤3.

Table 1

Table 2

As seen from Table 2, relative to comparative examples 1 to 5, the battery of embodiment 1 to 10 is at a high temperature of such as 60 DEG C, in floating charge With the high rate discharge in superior durability service life (cycle life) and low temperature environment in electricity.

In fig. 4 it is shown that embodiment 1 and Comparative Examples 1 and 2 and 5 battery pack 1C discharge curves, wherein horizontal axis expression put Electric depth (%), and the longitudinal axis indicates voltage (V).The discharge curve of the battery pack of embodiment 1 is similar to the lead accumulator of comparative example 5 The discharge curve of group, therefore the battery pack of embodiment 1 has excellent compatibility with lead accumulator.Moreover, the battery of embodiment 1 The discharge curve of group is more flat than the discharge curve of the lead accumulator group of comparative example 5, consequently found that it is under the discharge voltage of 12V With high stability.On the other hand, the discharge voltage of the battery pack of comparative example 1 and 2 is less than the lead accumulator group of comparative example 5 Discharge voltage, consequently found that they are bad with the compatibility of lead accumulator group.

The anode of Examples 1 and 2 and the potential curve of cathode are shown in Fig. 5.In Figure 5, horizontal axis indicates depth of discharge (%), And the longitudinal axis indicates potential (V, relative to Li/Li⁺).The lithium-absorbing of the positive electrode active materials of embodiment 1-release potential is 3.55 (V, relative to Li/Li⁺), lithium-absorbing-release potential of the positive electrode active materials of embodiment 2 is 3.85 (V, relative to Li/Li⁺), And the lithium-absorbing of the positive electrode active materials of comparative example 2-release potential is 3.45 (V, relative to Li/Li⁺).On the other hand, Lithium-absorbing-release potential of the negative electrode active material of Examples 1 and 2 and comparative example 2 is 1.55 (V, relative to Li/Li⁺).Cause This, the medium voltage (cell voltage of depth of discharge 50%) of Examples 1 and 2 and comparative example 2 be respectively 2.0V, 2.35V and 1.8V.Correspondingly, the medium voltage of the battery of embodiment 1 and the medium voltage of lead accumulator are identical, therefore the battery of embodiment 1 With the compatibility most excellent with lead accumulator.

From figure 5 it can be seen that the lithium-absorbing potential of the positive electrode active materials of Examples 1 and 2 depth of discharge be more than after 80% by Gradually reduce.Since the voltage of the battery of Examples 1 and 2 is continuously decreased when depth of discharge reaches 80%, it is possible to easily From voltage change measurement capacity and depth of discharge (DOD) (see Fig. 4).On the other hand, the lithium of the positive electrode active materials of comparative example 2 Under even if absorb potential still keeps stable when depth of discharge is more than 80%, and it is unexpected when depth of discharge is close to 100% Drop.Therefore, as shown in figure 4, the voltage of the battery of comparative example 2 reduces suddenly when depth of discharge is more than 90%.Therefore, comparative example 2 battery is difficult to from voltage change accurately measurement capacity and depth of discharge (DOD).

The nonaqueous electrolyte battery of at least one of the embodiment above and embodiment includes cathode, and it includes containing titanyl Compound；And anode, it includes by LiFe_1-xMn_xSO₄What F was indicated have it is at least one selected from water phosphorus lithium iron-stone crystal structure and The compound of the crystal structure of triplite crystal structure, wherein 0≤x≤0.2, therefore following non-aqueous solution electrolysis can be provided Electrolyte cell, with excellent high-temperature floating-charge electrical property and low-temperature and high-speed discharge performance and with the compatibility of lead accumulator, and And its capacity can be detected easily.

Notwithstanding certain embodiments, but these embodiments are merely exemplary, it is not intended to limit this hair Bright range.In fact, new embodiment as described herein can be presented as other forms, in addition, embodiment party as described herein The form of energy can carry out various omissions, substitute and change the spirit without departing from the present invention.Appended claims and its Equivalent intention covers such form or modification, and falls within the scope and spirit of the present invention.

Claims (13)

1. a kind of electrode, it includes by LiFe_1-xMn_xSO₄The compound that F is indicated, wherein 0≤x≤0.2, the compound has Triplite crystal structure.

2. electrode according to claim 1, wherein the value of x meets 0.1<x≤0.2.

3. electrode according to claim 1 or 2, wherein further include coating, the coating covers the compound At least part surface of particle, and include it is at least one be selected from carbon material, phosphorus compound, fluoride and metal oxide Material.

4. electrode according to claim 3, wherein the coating includes at least one selected from d₀₀₂For 0.344nm or bigger Carbonaceous material, Li₃PO₄、AlPO₄、SiP₂O₇、LiF、AlF₃、FeF_xWherein 2≤x≤3, Al₂O₃、ZrO₂、SiO₂And TiO₂Material Material.

5. electrode according to claim 3, wherein the amount of the amount of the particle based on the compound, the coating exists In the range of 0.001~3 weight %.

6. electrode according to claim 3, wherein the average primary particle diameter of the compound particle is at 0.05~1 μm In range.

7. electrode according to claim 1 or 2 is anode.

8. a kind of nonaqueous electrolyte battery, it includes：

Anode is electrode according to any one of claims 1 to 6；

Cathode, it includes titanium-containing oxides；With

Nonaqueous electrolyte.

9. nonaqueous electrolyte battery according to claim 8, wherein the titanium-containing oxide is selected from least one Li_4/3+xTi_5/3O₄Wherein 0≤x≤1, Li_xTiO₂Wherein 0≤x≤1 and Li_xNb_aTiO₇The oxidation of wherein 0≤x and 1≤a≤4 Object.

10. nonaqueous electrolyte battery according to claim 8 has wherein the titanium-containing oxide is at least one is selected from The Li-Ti oxide of spinel structure, the titanium oxide with bronze structures (B), with anatase structured titanium oxide, niobium The oxide of titanium oxide and Li-Ti oxide with ramsdellite structure.

11. a kind of battery pack, it includes the nonaqueous electrolyte batteries described in any one of claim 8~10.

12. a kind of battery pack, it includes battery module, the battery module includes the 6n or 5n claims 8 being connected in series with Nonaqueous electrolyte battery described in any one of~10, wherein n are 1 or larger.

13. a kind of vehicle, it includes the battery packs described in claim 11 or 12.