CN1905252A - Manganese dioxide, method and apparatus for producing the same, and battery active material and battery prepared by using the same - Google Patents
Manganese dioxide, method and apparatus for producing the same, and battery active material and battery prepared by using the same Download PDFInfo
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- CN1905252A CN1905252A CNA2006101074667A CN200610107466A CN1905252A CN 1905252 A CN1905252 A CN 1905252A CN A2006101074667 A CNA2006101074667 A CN A2006101074667A CN 200610107466 A CN200610107466 A CN 200610107466A CN 1905252 A CN1905252 A CN 1905252A
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Abstract
Manganese dioxide of this invention comprises monocrystalline particles with a beta-type crystal structure. The use of such manganese dioxide as an active material of a battery makes it possible to improve the discharge characteristics and long-term reliability of the battery.
Description
Background technology
Manganese dioxide is because aboundresources, low price, thereby is widely used as active material for positive electrode for battery.For example, manganese dioxide is normally used among the positive pole of the manganese cell of negative pole use zinc or the lithium battery of alkaline battery or negative pole use lithium metal etc.Especially, because lithium battery has good preservation characteristics, thereby not only is widely used as main power source, and be widely used as stand-by power supply.
In the past, as the manufacture method of battery, used usually and in acid solutions such as aqueous sulfuric acid, dissolved manganese mineral, the electrolysis of this solution of electrolysis (spy opens flat 6-1509914 communique) then with manganese dioxide.And disclose by electrolysis, can obtain tens of microns offspring.
Lighting and multifunction along with in recent years electronic instrument require the further high performance to battery such as flash-over characteristic and long-term reliability raising.But,, not talkatively necessarily fully satisfied above-mentioned requirements by the existing manganese dioxide that electrolysis or solid phase method obtain.For example, the manganese dioxide that obtains by electrolysis has polycrystalline structure, has crystal defect and/or crystal boundary.Therefore, it is believed that, hindered the diffusions in the manganese dioxide solid phase such as hydrogen ion, lithium ion, cause the flash-over characteristic of battery to reduce.
It is believed that the particle diameter of positive active material exerts an influence to the flash-over characteristic of battery.Because the average grain diameter of the manganese dioxide that obtains by electrolysis or solid phase method is greatly to tens of microns, thereby hydrogen ion and the displacement of lithium ion in manganese dioxide are long.Therefore, if, then be expected to improve flash-over characteristic by for example pulverizing with the manganese dioxide miniaturization.But,, average grain diameter is reached about 1 μ m even by miniaturization.In addition, this miniaturization also becomes the reason of expensiveization.
By using for example sol-gel process or spray heating decomposition, can make particle diameter is the following particulate of 1 μ m.But, the complex procedures of these methods and in manganese dioxide synthetic, need to expend time in, thereby be difficult to by using these methods to produce manganese dioxide in batches.
Summary of the invention
Therefore, the object of the present invention is to provide the flash-over characteristic that can improve battery and long-term reliability manganese dioxide, its manufacture method and device thereof, use active material for positive electrode for battery that this manganese dioxide makes and the battery that has used this active material.
The present invention relates to contain have the β type crystal structure manganese dioxide of monocrystal particle of (being crystalline texture).The average grain diameter of the monocrystal particle of manganese dioxide is preferably 0.1 μ m～1 μ m.This monocrystal particle preferably has the shape of particle of needle-like.And above-mentioned manganese dioxide preferably contains the monocrystal particle that has the β type crystal structure more than the 70 weight %.Wherein, the average grain diameter of monocrystal particle is meant, the mean value of the Breadth Maximum of manganese dioxide monocrystal particle.For example, under the situation of acicular particles, the average grain diameter of monocrystal particle is meant, the mean value of the length of the monocrystal particle of crystal growth direction (length direction).
In addition, the present invention relates to the manufacture method of above-mentioned manganese dioxide.This manufacture method comprises makes the aqueous solution that comprises manganese ion become subcritical state or supercriticality, thus the operation that manganese dioxide is separated out.
In above-mentioned manufacture method,, make it become subcritical state or supercriticality preferably by the aqueous solution that comprises manganese ion being heated with the programming rate more than 300 ℃/second.At this moment, more preferably, directly mix with the water of subcritical state or supercriticality by the aqueous solution that will comprise manganese ion, thereby the aqueous solution that comprises manganese ion is heated with the programming rate more than 300 ℃/second.
In above-mentioned manufacture method, in comprising the aqueous solution of manganese ion, be dissolved with oxidant, this oxidant preferably comprises and is selected from least a of oxygen, ozone gas, hydrogen peroxide and nitrate ion.
Under the aqueous solution that will comprise manganese ion and situation that the water of subcritical state or supercriticality directly mixes, also can dissolved oxidant in the water of subcritical state or supercriticality.As oxidant, can use and above-mentioned same oxidant.
In addition, the present invention relates to the manufacturing installation of above-mentioned manganese dioxide.This device comprises reaction tube, be connected the inlet side of reaction tube and supply with to reaction tube the aqueous solution that comprises manganese ion the 1st pipe, be connected the inlet side of reaction tube and supply with the 2nd pipe of water of subcritical state or supercriticality and the recovering mechanism of manganese dioxide that is arranged on outlet one side of reaction tube to reaction tube.The aqueous solution that comprises manganese ion mixes in the end of the inlet side of reaction tube with the water of subcritical state or supercriticality.The inner wall section of reaction tube is made of the insulating properties inorganic material.The insulating properties inorganic material is preferably quartz or aluminium oxide.
In addition, the present invention relates to by above-mentioned manganese dioxide and lithium compound heat are burnt till the active material for positive electrode for battery that synthesizes.In addition, above-mentioned manganese dioxide also can be used as positive active material.
Moreover, the present invention relates to a kind of battery, it comprises positive pole, negative pole, barrier film and the electrolyte that contains above-mentioned manganese dioxide or above-mentioned active material for positive electrode for battery.
Description of drawings
Fig. 1 is the skeleton diagram of an example showing the device be used to make manganese dioxide of the present invention.
Fig. 2 is the skeleton diagram of another example of showing the device be used to make manganese dioxide of the present invention.
Fig. 3 is for showing the skeleton diagram that converges part that is arranged on the pipe of the 1st in the device shown in Figure 2, the 2nd pipe and reaction tube.
Fig. 4 is the skeleton diagram in vertical section of the Coin-shaped battery of embodiment manufacturing.
Fig. 5 is the electron micrograph of the manganese dioxide of embodiment 1-2 manufacturing.
Fig. 6 is the X-ray diffractogram of the manganese dioxide of embodiment 1-2 manufacturing.
Fig. 7 is the electron micrograph of the manganese dioxide of embodiment 2-1 manufacturing.
Fig. 8 is the X-ray diffractogram of the manganese dioxide of embodiment 2-1 manufacturing.
Fig. 9 is the skeleton diagram that converges part of the 1st pipe, the 2nd pipe and the reaction tube of the manufacturing installation of employed manganese dioxide among demonstration comparative example 2-1 and the comparative example 2-2.
Embodiment
Manganese dioxide of the present invention contains the monocrystal particle with β type crystal structure.By using such manganese dioxide, can improve the flash-over characteristic and the long-term reliability of battery as the positive electrode for battery activating substance.
That is, in the manganese dioxide of existing polycrystalline structure, have crystal defect and crystal boundary, these crystal defects and crystal boundary have hindered hydrogen ion or lithium ion etc. and have spread in active material particle.But manganese dioxide of the present invention is above-mentioned monocrystalline, mainly comprises the particle that contains crystal defect etc. hardly, thereby compares more with the manganese dioxide of existing polycrystalline structure and can improve flash-over characteristic.That is, the manganese dioxide of the application of the invention can suppress for example rising of the inside battery resistance in discharge process.
Manganese dioxide of the present invention is substantially free of impurity such as lower oxyde, oxygen composition and the crystallization water etc., even when preserving, also is difficult for dissolving manganese ion from manganese dioxide.In addition, because manganese dioxide of the present invention mainly comprises monocrystal particle, thereby can suppress the corrosion etc. of crystal boundary, and surface energy is low.Therefore, compare with the existing manganese dioxide that mainly constitutes and to become stable, and be difficult for decomposing by the particle of polycrystalline structure.Therefore, can improve long-term reliability.
The average grain diameter of the monocrystal particle of manganese dioxide is preferably 0.1 μ m～20 μ m, more preferably 0.1 μ m～1 μ m.Reach below the 20 μ m by the average grain diameter that makes monocrystal particle, thereby needn't carry out pulverization process so that it becomes particulate manganese dioxide.Especially, if the average grain diameter of monocrystal particle is below the 1 μ m, then the diffusion length of hydrogen ion in the monocrystal particle and lithium particle shortens.Thereby can further improve the flash-over characteristic of battery.But the average grain diameter of monocrystal particle becomes difficult during with being mixed with of conductive auxiliary agent and adhesive less than the manganese dioxide of 0.1 μ m when making electrode.
Manganese dioxide of the present invention preferably contains the monocrystal particle that has the β type crystal structure more than the 70 weight %.
Manganese dioxide of the present invention can be by comprising manganese ion (Mn
2+) the aqueous solution make subcritical state or supercriticality is made.For example, when the aqueous solution that comprises manganese ion contained hydrogen peroxide as the oxidant that is used to promote the manganese ion oxidation, manganese dioxide was to generate according to following reaction equation.
The temperature of the aqueous solution by will comprising manganese ion is controlled at more than 250 ℃, its pressure is controlled to be more than the 20MPa, can make subcritical state to this aqueous solution of major general.And then the temperature of the aqueous solution by will comprising manganese ion is controlled at more than 374 ℃, its pressure is controlled to be more than the 22MPa, can make this aqueous solution become supercriticality.
Mn
2+Stably be present in the liquid easily in the ion that has electric charge.On the one hand, resembling the such apolar substance of manganese dioxide that is generated stably is present in the original gas easily.Therefore, particularly under supercriticality,, thereby promptly generate nonpolar manganese dioxide because the solvent of water and so on becomes gaseous state from liquid state.
Under supercriticality, the such solubility of metal oxide in water of manganese dioxide is under constant compression force, if the temperature of water rises, then solubility sharply reduces.Therefore, under supercriticality, under constant pressure, can be by elevating the temperature, can promote separating out as the manganese dioxide of reaction product.
In that hydro-thermal is synthetic to be made under the situation of metal oxide by carrying out, in the oxide that is generated, contain the compound of the crystallization water and/or hydroxyl usually under the lower temperature about 100～200 ℃.On the other hand, particularly under the situation of synthesis of metal oxide under the condition of high temperature as the supercriticality,, thereby in the oxide that is generated, contain the crystallization water etc. hardly because water becomes the gas shape.In addition, under such condition of high temperature, can synthesize the manganese dioxide of particulate and high crystalline.
Therefore, it is believed that, as described herein,, can promote the generation of the oxide that the crystallization degree is high, obtain the monocrystalline particulate of oxide easily by under subcritical state or under the supercriticality, synthesizing.
Especially, be that the manganese dioxide of the monocrystal particle of 0.1 μ m～1 μ m can be made by the following method as having β type crystal structure and average grain diameter: the aqueous solution that comprises manganese ion is heated so that it becomes subcritical state or supercriticality with the programming rate more than 300 ℃/second.
Below, the manufacture method of manganese dioxide of the present invention is carried out specific description.
(manufacture method 1)
Manganese dioxide of the present invention, particularly mainly contain average grain diameter greater than 1 μ m and can be by using device for example shown in Figure 1, make the aqueous solution that comprises manganese ion become subcritical state or supercriticality is made smaller or equal to the manganese dioxide of the monocrystal particle of 20 μ m.
Device shown in Figure 1 comprises the tube furnace 2 with heating wire 4 and is arranged on pipe 1 in the tube furnace 2.In pipe 1, be packaged with the aqueous solution (aqueous solution of raw material) that comprises manganese ion.Pipe 1 is fixed in the tube furnace 2 by anchor clamps 6.The space that pipe 1 is set in the tube furnace 2 is by bolt 5 sealings.Heating wire 4 passes through near the part the space that is provided with pipe in the body of tube furnace 2.In tube furnace 2, be provided with thermocouple 3.By thermocouple 3, measure the temperature in the tube furnace 2.
Use the manufacturing of the manganese dioxide of such device to carry out by the following method.
At first, in pipe 1, put into aqueous solution of raw material, will manage 1 sealing.Aqueous solution of raw material prepares by for example dissolve water-soluble manganese salt in distilled water.As manganese salt, can use various manganese salt.For example, can list Mn (NO
3)
2, and MnSO
4
The concentration of the manganese ion that is comprised in the aqueous solution of raw material is preferably 0.01～5mol/L.When the concentration of manganese ion during less than 0.01mol/L, the output of manganese dioxide reduces.If the concentration of manganese ion is higher than 5mol/L, then the productive rate of manganese dioxide reduces.
After enclosing aqueous solution of raw material in the pipe 1, will manage 1 and insert in the tube furnace 2.The encapsulation amount of the aqueous solution of raw material in pipe 1 is carried out to be adjusted so that the set point of temperature in tube furnace 2 is issued to goal pressure.Wherein, this pressure can be by being assumed to pure water with aqueous solution of raw material, and (Steam Table) calculates by steam table.For example, because reaction temperature is 400 ℃, reaction pressure is that the density of the water of 30MPa is 0.35g/cm
3, thereby, be for example 10cm if manage 1 volume
3, then at the aqueous solution of raw material of managing encapsulation 3.5g in 1.
Then, heat and reach the temperature of regulation, aqueous solution of raw material is made subcritical state or supercriticality with 2 pairs of tube furnaces pipe 1.Under this temperature, keep the reaction time (for example about 5～20 minutes) of regulation, synthetic manganese dioxide.Although depend on the conditions such as kind of aqueous solution of raw material, by temperature is set at more than 250 ℃, pressure is set at more than the 20MPa, can make aqueous solution of raw material become subcritical state at least.Preferably heating-up temperature and the amount that is encapsulated in the aqueous solution of raw material in the pipe 1 are regulated, thereby make aqueous solution of raw material become supercriticality.In addition, by temperature being set at more than 374 ℃, pressure being set at more than the 22MPa, can make aqueous solution of raw material become supercriticality.Reach of the decisions such as performance of the programming rate of afore mentioned rules temperature by tube furnace.Be used to make the temperature of aqueous solution of raw material to rise to afore mentioned rules temperature required time to be generally 30 seconds～about 2 minutes.For example, in said apparatus, programming rate can be 4 ℃/second.
About the heating-up temperature of tube furnace 2, while can use the temperature in 3 pairs of tube furnaces of thermocouple to measure, control.
Then, after the reaction time through regulation, will manage 1 and take out from tube furnace 2, and put into cold bath etc., making is swift in response stops.Then, by the solid constituent of separating out is filtered, washs, obtain particulate in pipe 1 as the manganese dioxide of reaction product.
By above-mentioned manufacture method, the average grain diameter that can obtain monocrystal particle greater than 1 μ m and smaller or equal to 20 μ m, be preferably greater than 1 μ m and smaller or equal to the manganese dioxide particulate of 10 μ m.Therefore, needn't carry out pulverization process to form particulate to resulting manganese dioxide.In addition, by said method, can make manganese dioxide by high productivity.
Wherein, the average grain diameter of so-called monocrystal particle is meant the mean value of the maximum gauge of manganese dioxide monocrystal particle.For example, under the situation of acicular particles, be meant the mean value of length of monocrystal particle of the direction of growth (length direction) of crystal.
Aqueous solution of raw material can comprise the oxidant that is used to promote the manganese ion oxidation.As oxidant, can use for example oxygen, ozone gas, hydrogen peroxide and nitrate ion.These materials can use separately, also two or more can be used in combination.By comprising such oxidant, can be with Mn
2+Promptly be oxidized to Mn
4+
For example, by using Mn (NO
3)
2, can in aqueous solution of raw material, add NO
3 -Ion.By this NO
3 -The existence of ion can promote Mn
2+Ion is to Mn
4+The oxidation of ion.
In addition, in pipe 1, there is air.At this moment airborne oxygen also plays a part oxidant.Therefore, more preferably there is oxygen in the gas phase in reaction tube 1.For the accelerating oxidation reaction, the amount of the oxygen that is comprised in the gas phase in pipe 1 is increased.
As oxidant, preferably nitrate ion is used in combination with hydrogen peroxide.Hydrogen peroxide easily resolves into the oxygen G﹠W by heating.Particularly under super critical condition, it is mutually uniform that oxygen and aqueous solution of raw material form, and therefore, comprises nitrate ion and hydrogen peroxide by oxidant, can form better oxidation reaction field.
(manufacture method 2)
The manganese dioxide that mainly contains average grain diameter and be the monocrystal particle of 0.1 μ m～1 μ m can make it become subcritical state or supercriticality is made by with the programming rate more than 300 ℃/second the aqueous solution (aqueous solution of raw material) that comprises manganese ion being heated.
Such manganese dioxide can use device for example shown in Figure 2 to make.In the device of Fig. 2, by pressure distilled water is heated to the temperature of regulation, thereby makes the water of subcritical state or supercriticality with regulation.The water of resulting subcritical state or supercriticality is directly mixed with aqueous solution of raw material, and with the programming rate heating raw aqueous solution more than 300 ℃/second, thereby make aqueous solution of raw material become subcritical state or supercriticality.
The device of Fig. 2 comprises reaction tube 26, supplies to the 1st feedway 21 in the reaction tube 26 and supply to the 2nd feedway 22 in the reaction tube 26 by the 2nd pipe 24 water with subcritical state or supercriticality by the 1st pipe 23 aqueous solution that will comprise manganese ion.This device further comprises the manganese dioxide recovering mechanism 29 that is arranged on the cast electric furnace 25 of the 2nd pipe in 24, is arranged on outlet one side of reaction tube 26, be arranged on cast electric furnace 27 in the reaction tube 26, be used to cool off reacting furnace heat exchanger 28, be used to reduce the counterbalance valve 30 and the liquid storage pool 31 of the pressure of reactant liquor.The inner wall section of reaction tube 26 is made of the insulating properties inorganic material.
The 1st feedway 21 comprises jar 21a that holds the aqueous solution that comprises manganese ion and the pump 21b that is used for supplying with authorized pressure the aqueous solution that comprises manganese ion.The 2nd feedway 22 comprises the jar 22a that holds distilled water and is used for supplying with authorized pressure the jar 22b of distilled water.As pump 21b and 22b, can use for example pulse-free flow pump etc.
Supply to the 2nd distilled water of managing in 24 by the 2nd feedway 22, be heated to more than 250 ℃, become the water of subcritical state or supercriticality by the tubular electric furnace 25 that is arranged in the 2nd pipe 24.At this moment, in distilled water,, apply the pressure of the regulation more than the 20MPa by the 2nd feedway 22 according to formed subcritical state or supercriticality.
The 1st pipe the 23 and the 2nd pipe 24 is connected the inlet side of reaction tube 26.In the end of the inlet side of reaction tube, the aqueous solution that comprises manganese ion mixes with the water of subcritical state or supercriticality.An example that converges part MP that in Fig. 3, has shown the reaction tube 26 of the 1st pipe the 23 and the 2nd pipe 24.
In Fig. 3, mix the formation reactant liquor at the 1st pipe the 23 and the 2nd pipe 24 the part MP with converging of reaction tube 26 from the 1st pipe 23 aqueous solution of raw material of being supplied with and from the water of the 2nd pipe 24 subcritical states of being supplied with or supercriticality.Aqueous solution of raw material contacts by the water with subcritical state or supercriticality, and with the heating of the programming rate more than 300 ℃/second, becomes subcritical state or supercriticality.In addition, in order to become subcritical state or supercriticality, apply authorized pressure more than the 20MPa by 21 pairs of aqueous solution of raw material of the 1st feedway.The 1st pipe and the 2nd pipe and the connected mode of reaction tube are if can then be not limited to mode shown in Figure 3 at the end mixed flow of the upstream of reaction tube one side through the aqueous solution of raw material of the 1st pipe and the flow through subcritical state of the 2nd pipe or the water of supercriticality.
Resulting reactant liquor is flow through from reaction tube 26.At this moment, heat reactant liquor so that it keeps subcritical state or supercriticality by 27 pairs of tubular electric furnaces.
After reactant liquor flows through from the reaction tube 26 of defined length, dual pipe type heat exchanger 28 coolings of downstream one side of reactant liquor by being arranged on reaction tube 26.The reactant liquor that has been cooled is by the recovering mechanism 29 of filter in the pipeline and so on.In recovering mechanism, pile up solid constituent is arranged.By washing this solid constituent, can obtain manganese dioxide.The counterbalance valve 30 of downstream one side of the reactant liquor that utilizes recovering mechanism 29 by being arranged on recovering mechanism 29 reduces its pressure.Reactant liquor after the step-down remains in the liquid storage pool 31.
As shown in Figure 3, in said apparatus, the inner wall section 32 of reaction tube 26 is formed by the insulation inorganic material, if use the insulating properties inorganic material, different with the situation of using stainless steel and other metal materials, the nucleus that can not cause manganese dioxide at the interface of reactant liquor and reaction tube generates, and only causes in reactant liquor that nucleus generates.Therefore, can prevent the obstruction of locking apparatus.
Above-mentioned insulating properties inorganic material is quartz glass or aluminium oxide more preferably.These materials are insulator, even and also be stable under supercriticality, therefore, can in long-time, stably carry out the synthetic continuously of manganese dioxide by using these materials.
In this manufacture method, comprise the aqueous solution of manganese with the heating of the programming rate more than 300 ℃/second.Like this, owing to can reach the high hypersaturated state of manganese dioxide in moment, thereby can produce the following nucleus of 1 μ m.In addition, owing to generate the nucleus of a plurality of manganese dioxide simultaneously, therefore can prevent because the aggegation of nuclear and on crystal surface the 2 times polycrystallization that karyogenesis caused.Particularly under supercriticality, can suppress because the growth of the manganese dioxide crystal that (Ostwald ripening phenomenon) caused is separated out in the dissolving again of crystallization.Therefore, can high productivity manufacturing average grain diameter be the following manganese dioxide monocrystal particle of 1 μ m.
In the device of Fig. 2, the water of aqueous solution of raw material with subcritical state or supercriticality can be mixed continuously.Can synthesize manganese dioxide continuously thus.
According to said method, be the following manganese dioxide particulate of 1 μ m owing to can synthesize average grain diameter, therefore needn't carry out pulverization process to resulting manganese dioxide particulate.But, if the programming rate of the aqueous solution that comprises manganese ion then cause the growth of nucleus easily, thereby average grain diameter is sometimes greater than 1 μ m less than 300 ℃/second.
As mentioned above, the aqueous solution that comprises manganese ion can directly mix with the water of subcritical state or supercriticality, and heats with the programming rate more than 300 ℃/second.The water of subcritical state or supercriticality can use method well known in the art to make.Perhaps, also can use firing equipment directly to heat the aqueous solution that comprises manganese ion with the programming rate more than 300 ℃/second.
In manufacture method of the present invention,, in distilled water, dissolve the aqueous solution that water-soluble manganese salt forms with manufacture method 1 the same also can the use as the aqueous solution that comprises manganese ion.Similarly, the concentration of the manganese ion that is contained in comprising the aqueous solution of manganese ion is preferably 0.01～5mol/L.
The aqueous solution that comprises manganese ion can comprise the oxidant of the oxidation that is used to promote manganese ion.Under the aqueous solution that will comprise manganese ion and situation that the water of subcritical state or supercriticality directly mixes, comprise in the aqueous solution of manganese ion and also can comprise oxidant, the water of subcritical state or supercriticality also can comprise oxidant.As oxidant, can use the material identical with manufacture method 1.
In having the reacting field of gas phase, make under the situation of manganese dioxide, the same with above-mentioned situation, in order to promote Mn
2+Oxidation, not only can in aqueous solution of raw material, add oxidant, can also in gas phase, comprise oxygen.At this moment, for the accelerating oxidation reaction, the amount of the oxygen that is comprised in the gas phase in the reaction tube is increased.Especially, under supercriticality, the gas that comprises the aqueous solution of manganese ion and oxygen and so on can form homogeneous phase.Therefore, cause the oxidation of manganese ion easily, can make manganese dioxide by high productivity.
As mentioned above, according to the manufacture method of present embodiment, can the high productivity manufacturing have the β type crystal structure, average grain diameter is the monocrystal particle manganese dioxide of 0.1 μ m～1 μ m.
Above-mentioned manufacture method 1 and manufacture method 2 resulting manganese dioxide can be as the positive active materials of battery.In addition, also can the positive active material of battery will be used as the synthetic compound of initiation material with resulting manganese dioxide.With purity height, the crystallinity height of above-mentioned manganese dioxide as the synthetic compound of initiation material, and average grain diameter is little.Therefore, comprise such compound and can improve charge-discharge characteristic and long-term reliability as the battery of active material.
For example, by above-mentioned manganese dioxide is mixed with lithium compound, and burn till (calcining) this mixture, can obtain the Mn oxide that comprises lithium of high-purity, high crystalline and the lithium manganese oxide of spinelle shape.As lithium compound, can use lithium hydroxide, lithium oxide etc.
Using such Mn oxide also is possible as the active material of battery.
Above-mentioned manganese dioxide and/or Mn oxide for example can be used as the positive active material of lithium primary battery, lithium secondary battery, alkaline battery and manganese cell.
Below, the present invention will be described based on embodiment.But these embodiment represent one embodiment of the invention, and the present invention is not limited to these embodiment.
(embodiment 1-1)
(manufacturing of manganese dioxide)
Use device shown in Figure 1, make manganese dioxide.
At stainless steel (SUS316) system volume is 5cm
3Pipe in, the encapsulation 1.31cm
3Manganese nitrate aqueous solution (manganese ion concentration: 1mol/L) (1.31g).The pipe that has encapsulated manganese nitrate aqueous solution is inserted in the tube furnace, and reaction is 10 minutes under 400 ℃ reaction temperature.At this moment pressure is 28MPa.In addition, programming rate at this moment is 4 ℃/second.
After 10 minutes reaction time finish, will manage and drop in the water-bath, make reaction stop.Then, the content of take-off pipe with washing with water after this content filtration, obtains manganese dioxide.The average grain diameter of resulting manganese dioxide monocrystal particle is 8 μ m.
(anodal manufacturing)
With above-mentioned resulting manganese dioxide, mix with 90: 5: 5 weight ratio, form anode mixture as the carbon black of conductive agent with as the fluororesin of adhesive.With this anode mixture press molding, make columned positive pole.In addition, positive pole was heat-treated under 250 ℃ before using to remove the water of attachment removal.
(manufacturing of negative pole)
Lithium is rolled plate strike out discoidly, make negative pole.
(preparation of electrolyte)
In propylene carbonate and 1, in the mixed solvent that the 2-dimethoxy-ethane mixes with volume ratio at 1: 1, with the concentration dissolving lithium perchlorate (LiClO of 1mol/L
4), preparation electrolyte.
(assembling of battery)
Use the above-mentioned positive pole that obtains, negative pole and electrolyte, the Coin-shape cell that has structure shown in Figure 4 by following step manufacturing.The external diameter of Coin-shape cell is that 20.0mm, thickness are 3.2mm.
The battery that obtains by above-mentioned steps is designated as battery 1-1.
(embodiment 1-2)
Respectively manganese nitrate and hydrogen peroxide are dissolved in the distilled water, make its concentration reach 1mol/L and 2mol/L respectively, obtain aqueous solution of raw material.Except using this aqueous solution of raw material, according to the step manufacturing manganese dioxide same with embodiment 1-1.The average grain diameter of resulting manganese dioxide monocrystal particle is 8 μ m.
Except using the manganese dioxide that obtains like this, according to the step manufacturing battery 1-2 same with embodiment 1-1 as the positive active material.
(embodiment 1-3)
Except the encapsulation amount of aqueous solution of raw material in pipe is 4.12cm
3(4.12g), reaction temperature is outside 250 ℃, according to making battery 1-3 with the same step of embodiment 1-2.In addition, the pressure during reaction is 28MPa.The average grain diameter of resulting manganese dioxide monocrystal particle is 20 μ m.
(embodiment 1-4)
Except the encapsulation amount of aqueous solution of raw material in pipe is 3.74cm
3(3.74g), reaction temperature is outside 300 ℃, according to making battery 1-4 with the same step of embodiment 1-2.In addition, the pressure during reaction is 28MPa.The average grain diameter of resulting manganese dioxide monocrystal particle is 15 μ m.
(embodiment 1-5)
With the resulting manganese dioxide of embodiment 1-1 and lithium hydroxide mixed in molar ratio according to 1: 0.5.Under 400 ℃, resulting mixture is heat-treated, obtain comprising the Mn oxide (Li of lithium
0.5MnO
2).The resulting Mn oxide that contains lithium is used as positive active material.With the Mn oxide that contains lithium of gained, mix at 90: 5: 5 with weight ratio and make anode mixture as the carbon black of conductive agent with as the fluororesin of adhesive, in addition, according to making battery 1-5 with the same step of embodiment 1-1.Battery 1-5 is a secondary cell.
(embodiment 1-6)
With the resulting manganese dioxide of embodiment 1-1 and lithium hydroxide mixed in molar ratio according to 1: 0.5.With 850 ℃ resulting mixture is heat-treated, obtain galaxite (LiMn
2O
4).Use resulting galaxite as positive active material.With the galaxite of gained, mix at 90: 5: 5 with weight ratio and make anode mixture as the carbon black of conductive agent with as the fluororesin of adhesive, in addition, according to making battery 1-6 with the same step of embodiment 1-1.Battery 1-6 is a secondary cell.
(comparative example 1-1)
Use with electrolytic manganese dioxide (average grain diameter is 30 μ m) as positive active material.In addition, because electrolytic manganese dioxide has the crystal structure that contains than the γ type of multi-crystallization water,, make it the crystal structure that phase transformation changes into the β type so electrolytic manganese dioxide is heat-treated with 400 ℃.Will by phase transformation change into the crystal structure of β type electrolytic manganese dioxide, mix at 90: 5: 5 with weight ratio as the carbon black of conductive agent with as the fluororesin of adhesive and make anode mixture, in addition, according to the step manufacturing comparison battery 1-1 same with embodiment 1-1.
(comparative example 1-2)
With electrolytic manganese dioxide (average grain diameter 30 μ m) and the mixed in molar ratio of lithium hydroxide according to 1: 0.5.With 400 ℃ resulting mixture is heat-treated, obtain comprising the Mn oxide (Li of lithium
0.5MnO
2).Except using the resulting Mn oxide that comprises lithium, according to the step manufacturing comparison battery 1-2 same with embodiment 1-1 as the positive active material.Relatively battery 1-2 is a secondary cell.
(comparative example 1-3)
With electrolytic manganese dioxide (average grain diameter 30 μ m) and the mixed in molar ratio of lithium hydroxide according to 1: 0.5.With 850 ℃ resulting mixture is heat-treated, obtain galaxite (LiMn
2O
4).Except using resulting galaxite, according to the step manufacturing comparison battery 1-3 same with embodiment 1-1 as the positive active material.Relatively battery 1-3 is a secondary cell.
Employed electrolytic manganese dioxide is block offspring among above-mentioned relatively battery 1-1～1-3, and is polycrystalline structure.The average grain diameter of crystallization that is comprised in the electrolytic manganese dioxide of polycrystalline structure is about 0.2 μ m.The average grain diameter of so-called here crystallization, the average grain diameter of the primary particle that is meant in the offspring to be comprised.
(making the evaluation method of sample)
By using CuK
αX-ray diffraction method (XRD) measure the crystal structure of the positive active material of manufacturing among the crystal structure of the positive active material of manufacturing in the crystal structure, embodiment 1-5～1-6 of the manganese dioxide of the foregoing description 1-1～1-4 manufacturing and the comparative example 1-1～1-3.The shape of the manganese dioxide of making by scanning electron microscope (SEM) observation post etc.
(evaluation result)
As an example, in embodiment 1-2 the SEM photo of the manganese dioxide of manufacturing as shown in Figure 5, X-ray diffractogram is as shown in Figure 6.By the X-ray diffractogram of the SEM photo of Fig. 5 and Fig. 6 as can be known, the impurity of employed manganese dioxide is few among the battery 1-2, and crystallinity is very high.Therefore, manganese dioxide of the present invention is suitable as for example positive electrode of lithium primary battery very much.
As the SEM photo of Fig. 5 observed to, the shape of the monocrystal particle of the manganese dioxide that embodiment 1-2 obtains is mainly needle-like.The length of this acicular crystal is the scope of 5 μ m～10 μ m, and its average length (average grain diameter) is 8 μ m.The width of this acicular crystal is the scope of 1 μ m～2 μ m.In reaction temperature was embodiment 1-3 and 1-4 below 374 ℃, the average grain diameter of resulting manganese dioxide monocrystal particle was respectively 20 μ m and 15 μ m.That is, the average grain diameter of the resulting manganese dioxide monocrystalline of embodiment 1-3 and 1-4 is bigger than the average grain diameter of the manganese dioxide monocrystal particle of embodiment 1-2.
In addition, former, the major part with manganese dioxide of β type crystal structure is the polycrystalline particle, does not have the manganese dioxide that contains the above monocrystal particle of 70 weight %.
In table 1, H when having shown in making battery 1-1～1-4 employed manganese dioxide
2O
2Add have or not, the productive rate of reaction temperature and manganese dioxide.The productive rate of manganese dioxide is meant, the ratio that the actual manganese dioxide that obtains is represented with percentage with respect to the amount of getable manganese dioxide in theory.
Table 1
| H 2O 2Interpolation | Reaction temperature (℃) | Product | Productive rate (%) | |
| Battery 1-1 | Do not have | 400 | | 29 |
| Battery 1-2 | Have | 400 | MnO 2 | 90 |
| Battery 1-3 | Have | 250 | MnO 2 | 32 |
| Battery 1-4 | Have | 300 | MnO 2 | 56 |
By the result of battery 1-1 shown in the table 1 and 1-2 as can be known, added H
2O
2The productive rate of manganese dioxide of battery 1-2 higher.Can think H thus
2O
2Has function as oxidant.
By the result of battery 1-2～1-4 as can be known, in reaction temperature was 250～400 ℃ temperature range, temperature was high more, and then the productive rate of manganese dioxide becomes high more.Hence one can see that, becomes subcritical state or supercriticality by making aqueous solution of raw material, can easily obtain manganese dioxide.
Making aqueous solution of raw material reach under the situation of supercriticality (embodiment 1-2) by coexistence hydrogen peroxide in aqueous solution of raw material, the productive rate of manganese dioxide raises.Can think that this result is because oxygen that hydrogen peroxide generation thermal decomposition generates and aqueous solution of raw material formation homogeneous phase, thus can carry out well manganese ion oxidation caused.
(evaluation of primary cell)
To as the battery 1-1～1-4 of primary cell and relatively each 10 of battery 1-1 discharge under the condition of 15k Ω to be reduced to 2.0V until cell voltage, obtain discharge capacity with respect to per unit weight manganese dioxide.In each battery, resulting 10 discharge capacity value are average, try to achieve mean value.
Make each 20 of battery 1-1～1-4 and comparative example battery 1-1 carry out pre-arcing until 75% of the discharge capacity that reaches battery.After the discharge,,, measure internal resistance, try to achieve its mean value by the alternating voltage (AC impedence method) that applies 1kHz for each battery.Then, under 60 ℃, each battery was preserved 40 days.Can think, be equivalent to the situation in 2 years of preservation under the room temperature in the preservation under this condition.
After preserving, with the same before the preservation, measure internal resistance, obtain mean value.Resulting result is as shown in table 2.In table 2, shown that mean value with respect to the discharge capacity of the manganese dioxide of per unit weight is (in table 2, be designated as discharge capacity) and the mean value of the internal resistance value before preservation and the mean value (in table 2, being designated as internal resistance value) of the internal resistance value after the preservation.In table 2, also shown to have or not and added H
2O
2, reaction temperature and manganese dioxide monocrystal particle average grain diameter.
Table 2
| H 2O 2Interpolation | Reaction temperature (℃) | Average grain diameter (μ m) | Discharge capacity (mAh/g) | Internal resistance value (Ω) | ||
| Before the preservation | After the preservation | |||||
| Battery 1-1 | Do not have | 400 | 8 | 275 | 11 | 21 |
| Battery 1-2 | Have | 400 | 8 | 280 | 12 | 15 |
| Battery 1-3 | Have | 250 | 20 | 265 | 10 | 33 |
| Battery 1-4 | Have | 300 | 15 | 271 | 9 | 25 |
| Compare battery 1-1 | - | - | - | 260 | 11 | 112 |
By the result of the battery 1-1～1-4 of table 2 and comparative example 1-1 as can be known, manganese dioxide of the present invention is compared with existing manganese dioxide, and the discharge capacity of per unit weight increases more than about 10mA.It is believed that this is because manganese dioxide of the present invention has the structure of monocrystalline or near single, has crystal boundary in particle hardly, therefore can successfully carry out the interior diffusion of solid phase of manganese ion.
The discharge capacity of battery 1-2 is greater than the discharge capacity of battery 1-1 as can be known.It is believed that this is because by add H in aqueous solution of raw material
2O
2, the crystallinity of the manganese dioxide that is generated raises, and its utilance improves.
By the result of battery 1-2 and battery 1-3 as can be known, the reaction temperature when manganese dioxide is synthetic is high more, and then discharge capacity becomes big more.When making manganese dioxide, by making aqueous solution of raw material become subcritical state and then becoming supercriticality, the crystallinity of manganese dioxide further improves, and its utilance also improves.
Battery 1-1～1-4 compares with comparison battery 1-1, and the internal resistance value after the preservation is lower.Therefore, among battery 1-1～1-4 among employed manganese dioxide and the comparative example 1-1 employed existing manganese dioxide compare more stable.Manganese dioxide of the present invention has the structure of mono-crystalline structures or near single, contains crystal defect and lower oxyde hardly, the sulfur-bearing acid group and the crystallization water hardly in crystal structure.Therefore can think, can suppress the stripping of manganese, can suppress the increase of internal resistance from manganese dioxide.
The internal resistance value of internal resistance value after the preservation of battery 1-2 after as can be known less than the preservation of battery 1-1.When making this manganese dioxide, by in aqueous solution of raw material, adding H
2O
2, the crystallinity of manganese dioxide further improves.Therefore can think, can suppress the stripping of manganese.
By the result of battery 1-2 and battery 1-3 as can be known, reaction temperature is high more, and the internal resistance value after then preserving becomes more little.It is believed that this is because by making aqueous solution of raw material become subcritical state or supercriticality, the crystallinity of the manganese dioxide that is generated improves, and can suppress the stripping of manganese.
(evaluation of secondary cell)
For as the battery 1-5 of secondary cell and each 10 battery of battery 1-2 relatively, with the current value of 0.1mA, in 2.5～3.5V battery voltage range, discharge and recharge repeatedly.Obtain 50% the period that discharge capacity becomes the discharge capacity (hereinafter referred to as initial discharge capacity) of the 1st circulation.
Similarly, for the battery 1-6 that makes secondary cell and each 10 battery of battery 1-3 relatively, with the current value of 0.1mA, in 3.5～4.5V battery voltage range, discharge and recharge repeatedly.Obtain 50% the period that discharge capacity becomes initial discharge capacity.
The discharge capacity of battery 1-5 is reduced to 50% period of initial discharge capacity and compares with battery 1-2 relatively, has increased about 20%.The discharge capacity of battery 1-6 is reduced to 50% period of initial discharge capacity and compares with battery 1-3 relatively, has increased about 25%.
(embodiment 2-1)
Use Fig. 2 and device shown in Figure 3, make manganese dioxide.As the insulating properties inorganic material of the interior section 32 that constitutes reaction tube 26, use quartz glass.In addition, the constituent material as the Outboard Sections of the 1st pipe the 23 and the 2nd pipe 24 constituent material and reaction tube 26 uses stainless steel.
As aqueous solution of raw material, use the manganese nitrate aqueous solution of 0.05mol/L.Under the pressure of regulation, supply with this manganese nitrate aqueous solution by the 1st feedway 21.Be dissolved in aquae hydrogenii dioxidi in distilled water as the hydrogen peroxide of oxidant with the concentration of 0.1mol/L with the pressure feed of regulation by the 2nd feedway 22.In this supply process,, make supercritical water by circuit 25 these hydrogen peroxide of heating.
Manganese nitrate aqueous solution and supercritical water are converged, form reactant liquor.At this moment, regulate electric furnace 25 and 27 and counterbalance valve 30, make the temperature of converging the reactant liquor among the part MP reach 400 ℃, its pressure reaches 30MPa.In addition, the programming rate of aqueous solution of raw material is 322 ℃/second.
Then, washing is deposited in the solid constituent in the recovering mechanism 29, obtains manganese dioxide.Resulting manganese dioxide monocrystal particle has the β type crystal structure, and average grain diameter is 0.4 μ m.
The manganese dioxide that use obtains by said method, the same with embodiment 1-1, make battery 2-1.
(embodiment 2-2)
When making manganese dioxide, use the manganese nitrate aqueous solution of 0.05mol/L, in distilled water, do not add oxidant, in addition, according to the step manufacturing battery 2-2 same with embodiment 2-1.In addition, the temperature and pressure of the reactant liquor in converging part MP is identical with embodiment 2-1.The average grain diameter of the manganese dioxide monocrystal particle that present embodiment obtains is 0.4 μ m.
(embodiment 2-3)
When making manganese dioxide, the temperature of the reactant liquor in will converging part MP is set at 300 ℃, according to the step manufacturing battery 2-3 same with embodiment 2-1.In addition, the temperature and pressure of the reactant liquor in converging part MP is identical with embodiment 2-1.The average grain diameter of the manganese dioxide monocrystal particle that present embodiment obtains is 0.7 μ m.
(embodiment 2-4)
When making manganese dioxide, the temperature of the reactant liquor in converging part MP is set at 250 ℃, pressure and is set at the 30MPa, according to making battery 2-4 with the same step of embodiment 2-1.The average grain diameter of the manganese dioxide monocrystal particle that present embodiment obtains is 0.9 μ m.
(embodiment 2-5)
With the resulting manganese dioxide of embodiment 2-1 and lithium hydroxide mixed in molar ratio, obtain mixture according to 1: 0.5.With 400 ℃ resulting mixture is heat-treated, obtain comprising the Mn oxide (Li of lithium
0.5MnO
2).Except using the resulting Mn oxide that comprises lithium, according to the step manufacturing battery 2-5 same with embodiment 2-1 as the positive active material.Battery 2-5 is a secondary cell.
(embodiment 2-6)
With the resulting manganese dioxide of embodiment 2-1 and lithium hydroxide mixed in molar ratio according to 1: 0.5.With 850 ℃ resulting mixture is heat-treated, obtain galaxite (LiMn
2O
4).Except using resulting galaxite, according to the step manufacturing battery 2-6 same with embodiment 2-1 as the positive active material.Battery 2-6 is a secondary cell.
(generating the evaluation method of sample)
The same with said method, the crystal structure of the positive active material of the manganese dioxide of manufacturing and embodiment 2-5～2-6 manufacturing, shape etc. among mensuration the foregoing description 2-1～2-4.
(evaluation result)
As an example, Fig. 7 and Fig. 8 have shown the SEM photo and the X-ray diffractogram of the manganese dioxide of embodiment 2-1～2-4 manufacturing respectively.
By Fig. 7 and Fig. 8 as can be known, the resultant manganese dioxide of embodiment 2-1 is impure hardly, mainly contains the high acicular microparticles of monocrystalline.In addition, the average grain diameter of the manganese dioxide monocrystal particle of embodiment 2-1 is 0.4 μ m.On the other hand, as shown in Figure 5, the average grain diameter of the manganese dioxide monocrystal particle that embodiment 1-2 obtains is 8 μ m.Therefore, the manganese dioxide that embodiment 2-1 obtains is the littler particulate of average grain diameter, therefore is suitable as very much the positive electrode of lithium primary battery.
In addition, under reaction temperature was situation below 374 ℃, the average grain diameter of the manganese dioxide of manufacturing had the tendency that becomes big.
H when secondly, the manganese dioxide that has provided embodiment 2-1～2-4 in table 3 is made
2O
2Add have or not, the productive rate of reaction temperature and manganese dioxide.
Table 3
| H 2O 2Interpolation | Reaction temperature (℃) | Product | Productive rate (%) | |
| Battery 2-1 | Have | 400 | MnO 2 | 95 |
| Battery 2-2 | Do not have | 400 | MnO 2 | 35 |
| Battery 2-3 | Have | 300 | MnO 2 | 67 |
| Battery 2-4 | Have | 250 | MnO 2 | 41 |
By the result of embodiment 2-1 and embodiment 2-2 as can be known, reactant liquor comprises H
2O
2The productive rate of manganese dioxide of embodiment 2-1 become higher.Can think H thus
2O
2Play a part oxidant.That is, can think, the oxygen that hydrogen peroxide generation thermal decomposition generates under the supercriticality, form all-mutually, can carry out the oxidation of manganese ion well with the aqueous solution that comprises manganese ion.
By the result of embodiment 2-1, embodiment 2-3 and embodiment 2-4 as can be known, in 250～400 ℃ temperature range, if temperature is high more, then productive rate is high more.Therefore, become subcritical state or supercriticality, can easily obtain the less manganese dioxide of average grain diameter of monocrystal particle by making the aqueous solution that comprises manganese ion.
(evaluation method of primary cell)
For primary cell 2-1～2-4, according to step same as described above, the internal resistance value after obtaining discharge capacity and preserving preceding and preservation.Resulting result is as shown in table 4.In table 4, battery 1-2 and the result who compares battery 1-1 have also been shown.In addition, in table 4, also shown H
2O
2Add have or not, the average grain diameter of reaction temperature and manganese dioxide monocrystal particle.
Table 4
| H 2O 2Interpolation | Reaction temperature (℃) | Average grain diameter (μ m) | Discharge capacity (mAh/g) | Internal resistance value (Ω) | ||
| Before the preservation | After the preservation | |||||
| Battery 2-1 | Have | 400 | 0.4 | 300 | 7 | 16 |
| Battery 2-2 | Do not have | 400 | 0.4 | 295 | 8 | 23 |
| Battery 2-3 | Have | 300 | 0.7 | 285 | 9 | 26 |
| Battery 2-4 | Have | 250 | 0.9 | 280 | 10 | 32 |
| Battery 1-2 | Have | 400 | 8 | 280 | 12 | 15 |
| Compare battery 1-1 | - | - | - | 260 | 11 | 112 |
By battery 2-1～2-4 and relatively battery 1-1 the result as can be known, use and mainly to contain the battery of manganese dioxide that average grain diameter is the monocrystal particle of 0.1 μ m～10 μ m, compare with the comparison battery 1-1 that uses existing electrolytic manganese dioxide, discharge capacity has increased more than about 20mAh.Because employed manganese dioxide has the structure of monocrystalline and near single, thereby has the grain boundary in manganese dioxide particle hardly.And the average grain diameter of manganese dioxide particle is little.It is believed that the displacement of lithium ion in manganese dioxide particle shortens, lithium ion can successfully spread in manganese dioxide particle simultaneously, so discharge capacity is improved.
In addition, the discharge capacity of battery 2-1 is bigger than the discharge capacity of battery 2-2.It is believed that, comprise H by reactant liquor
2O
2, the crystallinity of manganese dioxide improves, and its utilance also improves.
By the result of battery 2-1, battery 2-3 and 2-4 as can be known, reaction temperature is high more, and the discharge capacity of battery is big more.It is believed that this is that its utilance improves because by making the aqueous solution that comprises manganese ion become subcritical state or supercriticality, the crystallinity of manganese dioxide improves.
The discharge capacity of battery 2-1～2-4 is identical or bigger with the discharge capacity of battery 1-2.Can think that this is because be controlled at 0.1～1 μ m by the average grain diameter with the manganese dioxide monocrystal particle, has shortened the diffusion length of lithium ion, has improved utilance.
Battery 2-1～2-4 compares with comparison battery 1-1 as can be known, and the internal resistance value after the preservation is low.It is believed that this is because with above-mentioned same, manganese dioxide of the present invention has the structure of monocrystalline or near single, does not contain crystal defect and lower oxyde, not the sulfur-bearing acid group and the crystallization water in crystal structure.Therefore, the stripping of manganese has obtained inhibition, and the increase of internal resistance has also obtained inhibition.
The internal resistance value of internal resistance value after the preservation of battery 2-1 after than the preservation of battery 2-2 is little as can be known.Comprise H by reactant liquor
2O
2, the crystallinity of manganese dioxide improves, and the stripping of manganese has also obtained inhibition.
By the result of battery 2-1, battery 2-3 and 2-4 as can be known, reaction temperature is high more, and the internal resistance value after the preservation is also more little.It is believed that, this be because, become subcritical state or supercriticality by making the aqueous solution that comprises manganese ion, the crystallinity of manganese dioxide improves, the stripping of manganese has also obtained inhibition.
(evaluation of secondary cell)
For battery 2-5 and 2-6,, obtain 50% the period that discharge capacity becomes initial discharge capacity also according to the step same with said method as secondary cell.
The discharge capacity of battery 2-5 becomes 50% period of initial discharge capacity, and comparing with battery 1-2 has relatively increased about 20%.The discharge capacity of battery 2-6 becomes 50% period of initial discharge capacity, and comparing with battery 1-3 has relatively increased about 25%.
From the above, comprise manganese dioxide battery of the present invention and compare with the battery that comprises existing manganese dioxide, the resistance value after the preservation reduces.In addition also as can be known, even using by under with the situation of manganese dioxide of the present invention as initiation material, the active material for anode of secondary cell that obtains by processing etc., also can produce the feature of manganese dioxide of the present invention, use the charge and discharge circulation life of the battery of this positive active material to improve.
In addition, even manganese dioxide of the present invention is mixed use with other active material, also can access above-mentioned effect.In this case, manganese dioxide of the present invention preferably accounts for more than the 10 quality % of active material admixture.
(embodiment 2-7)
Except using the reaction tube that inwall forms by aluminium oxide, according to the step manufacturing manganese dioxide same with embodiment 2-1.In the present embodiment, it is identical with embodiment 2-1 to converge the temperature and pressure of the reactant liquor among the part MP.The average grain diameter of the manganese dioxide monocrystal particle that present embodiment obtains is 0.4 μ m.
(comparative example 2-1 and comparative example 2-2)
Use device shown in Figure 2.In comparative example 2-1, reaction tube only is made of stainless steel.In comparative example 2-2, reaction tube only is made of copper.At the inlet of reaction tube, connect the 1st pipe and the 2nd pipe according to mode shown in Figure 9.
Except using said apparatus, according to embodiment 2-1 similarly step begin the synthetic of manganese dioxide.But in comparative example 2-1, after beginning synthetic 40 minutes, in comparative example 2-2, after beginning synthetic 30 minutes, the manganese dioxide that is generated causes the obstruction of device (reaction tube).
In embodiment 2-1 and the employed device of 2-7, after manganese dioxide synthetic carries out 5 hours, on the internal face of reaction tube, do not confirm to have separating out of manganese dioxide yet.Therefore, the material as the inside that constitutes reaction tube in order to suppress manganese dioxide separating out on the internal face of reaction tube, preferably uses insulating properties inorganic material such as quartz glass, aluminium oxide.
As mentioned above, the stripping that manganese dioxide of the present invention is mixed at the manganese in when discharge can be suppressed, and therefore can reduce the generation of the problems such as increase, discharge failure of inside battery resistance.By using such manganese dioxide, can improve the life characteristic of battery, and improve the reliability of battery.
By making the aqueous solution that comprises manganese ion become subcritical state or supercriticality, can the high manganese dioxide of synthetic single crystal.Especially, in supercriticality, if coexistence is as the nitrate ion and the oxygen of oxidant in reacting field, the aqueous solution and the oxygen that then comprise manganese ion can further form homogeneous phase, thereby can the synthetic manganese dioxide of high productivity.In addition, the average grain diameter of the particle that is generated is below the 20 μ m, need not pulverizing process.Therefore, can save size reduction energy.Therefore, by said method, can at a high speed, efficiently, low energy consumption synthesize the manganese dioxide monocrystal particle that battery behavior is improved.
Claims (14)
1. manganese dioxide, it contains the monocrystal particle with β type crystal structure.
2. manganese dioxide according to claim 1, wherein, the average grain diameter of described monocrystal particle is 0.1 μ m～1 μ m.
3. manganese dioxide according to claim 1, wherein said monocrystal particle has the shape of particle of needle-like.
4. the manufacture method of manganese dioxide, thus it comprises and makes the aqueous solution that contains manganese ion become the operation that subcritical state or supercriticality are separated out manganese dioxide.
5. the manufacture method of manganese dioxide according to claim 4 wherein, heats the described aqueous solution that comprises manganese ion with the programming rate more than 300 ℃/second, makes it become subcritical state or supercriticality.
6. the manufacture method of manganese dioxide according to claim 5, wherein, directly mix with the water of subcritical state or supercriticality by the described aqueous solution that will comprise manganese ion, thereby with the described aqueous solution that comprises manganese ion of the heating of the programming rate more than 300 ℃/second.
7. the manufacture method of manganese dioxide according to claim 4 wherein, comprises in the described aqueous solution of manganese ion and is dissolved with oxidant, and described oxidant comprises and is selected from least a of oxygen, ozone gas, hydrogen peroxide and nitrate ion.
8. the manufacture method of manganese dioxide according to claim 6 wherein, is dissolved with oxidant in the water of described subcritical state or supercriticality, and described oxidant comprises and is selected from least a of oxygen, ozone gas, hydrogen peroxide and nitrate ion.
9. the manufacturing installation of manganese dioxide, it comprises reaction tube, be connected the inlet side of reaction tube and supply with to reaction tube the aqueous solution that comprises manganese ion the 1st pipe, be connected the inlet side of reaction tube and supply with the 2nd pipe of water of subcritical state or supercriticality and the recovering mechanism of manganese dioxide that is arranged on outlet one side of reaction tube to reaction tube; Wherein,
The described aqueous solution that comprises manganese ion mixes in the end of the inlet side of reaction tube with the water of subcritical state or supercriticality;
Wherein the inner wall section of reaction tube is made of the insulating properties inorganic material.
10. the manufacturing installation of manganese dioxide according to claim 9, wherein said insulating properties inorganic material is quartz or aluminium oxide.
11. contain the active material for positive electrode for battery of the described manganese dioxide of claim 1.
12. by described manganese dioxide of claim 1 and lithium compound are burnt till the active material for positive electrode for battery that synthesizes.
13. a battery, it comprises positive pole, negative pole, barrier film and the electrolyte that contains claim 11 or 12 described active material for positive electrode for battery.
14. manganese dioxide according to claim 1, it comprises the monocrystal particle that has described β type crystal structure more than the 70 weight %.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005214771 | 2005-07-25 | ||
| JP214771/2005 | 2005-07-25 | ||
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|---|---|---|---|
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102560526A (en) * | 2011-12-23 | 2012-07-11 | 苏州大学 | Preparation method of high-power electrolytic manganese dioxide |
| CN103260742A (en) * | 2011-12-20 | 2013-08-21 | 韩华石油化学株式会社 | Preparation of electrode-active material by using double-pipe type heat exchanger |
| CN108147463A (en) * | 2017-11-24 | 2018-06-12 | 上海巴安水务股份有限公司 | A kind of automatic system for preparing aqua oxidation manganese solution |
-
2006
- 2006-07-25 CN CNA2006101074667A patent/CN1905252A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103260742A (en) * | 2011-12-20 | 2013-08-21 | 韩华石油化学株式会社 | Preparation of electrode-active material by using double-pipe type heat exchanger |
| CN102560526A (en) * | 2011-12-23 | 2012-07-11 | 苏州大学 | Preparation method of high-power electrolytic manganese dioxide |
| CN102560526B (en) * | 2011-12-23 | 2015-03-25 | 苏州大学 | Preparation method of high-power electrolytic manganese dioxide |
| CN108147463A (en) * | 2017-11-24 | 2018-06-12 | 上海巴安水务股份有限公司 | A kind of automatic system for preparing aqua oxidation manganese solution |
| CN108147463B (en) * | 2017-11-24 | 2023-11-24 | 上海巴安水务股份有限公司 | System for automatically preparing hydrated manganese oxide solution |
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