CN1036105A - Rechargeable battery - Google Patents

Abstract

A rechargeable battery comprises positive electrode, negative electrode and non-aqueous eletrolyte, wherein, positive electrode comprises that a sodium-cobalt/cobalt oxide is as main component, negative electrode is by containing sodium alloy, for example sodium/lead or sodium/ashbury metal, the synthetic of material with carbon element and adhesive is formed, non-aqueous eletrolyte is made up of sodium salt and ether compound, just, negative electrode is prepared by a kind of method, wherein, adhesive expands or is dissolved in the organic solvent, expands or the adhesive of dissolving mixes with material with carbon element, then this mixture is directly mixed with sodium alloy or sodium-cobalt/cobalt oxide or removes mixing again behind the organic solvent.

Description

Rechargeable battery

The present invention relates to a kind of rechargeable battery with high-energy-density, low self-discharge speed and long circulation life.

Prior art has been released a kind of the rechargeable battery of lithium metal (a kind of alkali metal) as negative electrode, this rechargeable battery is for example at " power supply magazine " (Journal of Power Sources) 12, the existing description in the 83-144 page or leaf (1984, people such as M.Hughes work).About the problem of lithium metal negative electrode, point out in the document, because lithium is very active; it and electrolyte (especially alkali) react, and form dielectric film ， And causes dendrite when charge and discharge growth; often cause the reduction of charge and discharge efficient, or often cause short circuit between the positive and negative electrode.As the means of head it off, proposed lithium/aluminium alloy on probation and manufactured negative electrode, so that reduce activity and the control and the electrolytical reaction of negative electrode.Yet, known that alloy can powder and be easy to fragmentation if repeat charge and discharge cycle.The result of the test of lithium alloy electrode characteristic of utilizing other metal at " J.Electrochem.Soc.; " 118, NO.10,1547-1549(1971) page or leaf, author: A.N.Dey " in existing the announcement; in the document, show at lithium and be selected from the alloy of a kind of metal among Sn, Pb, Al, Au, Pt, Zn, Cd, Ag and the Mg, and at lithium with form the Li of composition of the metal (as Ti, Cu and Ni) of rigid alloy ⁺Electroplate the comparative test result of current potential and electroplating current efficiency change.

In addition, Japan has proposed a kind of rechargeable battery among the unexamined patent publication number 48-24302, it includes as the lithium of the active material of negative electrode with as the nickel halogenide of the active material of positive electrode, wherein, for the electrical efficiency And that fills that improves lithium electrode realizes good maintainability, substitute the lithium sheet with a kind of pulverulent mixture that contains the lithium powder, this pulverulent mixture is with permanent conductive materials (as nickel powder or the crystalline carbon of degaussing), is adhered on the grid supporting construction by adhesive (as polyethylene or carboxymethyl cellulose).

A kind of two charge type lithium negative electrodes that are specially adapted to rely on the battery of ionomer work have been proposed in the Japanese unexamined patent (publication number 59-14264 number), it is a kind of flexible complex anode, this anode comprises a kind of alloy that contains lithium and segmentation or interphase (as lithium/aluminium, lithium/silicon, lithium/antimony, lithium/bismuth or lithium/boron, or the lithium of segmentation), a kind ofly has the plastics of ionic conductivity or a carbonaceous additive of elastic type polymeric material and a kind of segmentation (as carbon black or graphite).

In the Japanese unexamined patent (publication number 59-132576 number) a kind of lithium negative electrode has been proposed, this electrode comprises that one deck can form the conducting polymer of introducing the compound that lithium ion is arranged, this polymeric layer is placed on the lithium surface, and is relative with the active material of positive electrode of lithium rechargeable batteries.In addition, Japanese unexamined patent (publication number 59-157973 number) has proposed a kind of electrode of rechargeable battery, and this electrode includes one deck and is formed on the lip-deep carbon fiber layer of alkali metal.In addition, in the Japanese unexamined patent (publication number 59-186274 number) a kind of rechargeable battery has been proposed, it includes the negative electrode that utilizes a kind of material to form, this material can adsorb alkali metal ion when charging, when discharge, discharge alkali metal ion, be a kind of fusible metal alloy, alkali metal and negative electrode material Ya Ji And gather together in this alloy, so that submit cycle life to.

Japanese unexamined patent discloses 60-262351 number proposition and utilizes the compound of lithium alloy and conductive organic polymer to obtain negative electrode, even if this negative electrode also is so under the situation of the high utility ratio of lithium, the reduction of performance can not take place also.In addition, Japanese unexamined patent discloses 61-245474 and has proposed a kind of not moisture rechargeable battery, and this battery is made of a kind of polymer (this polymer has the main chain that conjugated structure is arranged) and a kind of material or a kind of material that alkali metal ion is arranged of wherein introducing with alkali-metal alloy of can forming.

In addition, disclose in Japanese unexamined patent and to disclose a kind of not moisture rechargeable battery among the 62-140358, it include be formed on the fusible metal alloy negative electrode, contrary with electrode to lip-deep conductive polymer membrane.Disclose in Japanese unexamined patent and to disclose a kind of not moisture rechargeable battery in 62-226536 number, it includes a negative electrode, this negative electrode has the lithium that is adsorbed in the negative electrode constituting body, and this electrode constituting body is made of the mixture of the metal that can form the alloy with lithium or mixture with lithium alloy powder of powdered graphite.

Many reports relate to alkali metal battery, and this class battery includes a positive electrode, and this positive electrode can be made of in charge and discharge time absorption and the inorganic oxide or the inorganic Calcogenide that discharge alkali metal ion a kind of.At " solid state chemistry magazine " (Journal of Solide State Chemistry) 6,532-537 page or leaf (1973 by people such as Calude work) and " solid ionic " (Solid State Inonics) 3-4, the 165-169 page or leaf has reported that the electrochemistry of sodium and sodium-cobalt/cobalt oxide is mingled with situation in (1981, by people such as Claude Delmas work).Relate in the document of sodium-cobalt/cobalt oxide at these, illustrated when the different various oxides of crystal structure by electrochemical oxidation or when being reduced, P ₂Phase (wherein oxide structure is prismatic) changes without undergoing any structure on the wide region of sodium ion quality.Ge plays  Ke copper-nickel alloy crook   chirp in Meng rice saddle cloth Ke  blood clam to sharpen the fine and soft handle of the Big Dipper Zhe of a peaceful water caltrop cyperus malaccensis

Disclose the example that discloses the manufacturing battery in 61-245474 number at Japan Patent, its method is to make positive electrode with sodium-cobalt/cobalt oxide.In this example, use powdery NaPb _0.26Sn _0.74Alloy, many P-phenylenes and polypropylene adhesive are made negative electrode.

Up to the present multiple electrolyte as alkali metal battery has been proposed.As solvent, carbon propylene (PC) commonly used, methyl-sulfoxide (DMSO), dimethylformamide(DMF), oxolane (THF), 2-dimethyl-tetrahydrofuran (MTHF) and 1,3-dioxolanes (DOL), this mentions in " power supply magazine " (Journal of Power Sources) 12, the 83-144 pages or leaves (1984)." basic electrochemical measuring method " (Basic Electrochemical Measurement Methods) (editing) by Association of Electrochemistry " in the 30-44 page or leaf in described organic solvent and electrolyte in detail.In Japanese unexamined patent (publication number 62-29070 number), disclose a kind of battery, used dialkyl ethers macrogol ester and carbon propylene in this battery as solvent, so that improve the storage characteristics of lithium battery.Before this patent disclosure, at " power supply magazine " (Journal of Power Sources) 12, reported a kind of mixed solvent that has satisfactory electrical conductivity and utilized solubility effect in the 53-59 page or leaf (1984) (author: Shinichi Tobishima and Akihiko Yamaki), this solvent includes carbon propylene and diethylene glycol dimethyl ether, triglyme or tetraethylene glycol dimethyl ether.

However, the practical Dian Chi And that can compare with existing acid-excide battery or nickel-cadmium cell does not develop from above-mentioned suggestion.The battery that above-mentioned document or patent document are mentioned have cause can not practical application difficult problem.These problems that are checked through and essence " Junichi Yamamoto; electrochemistry (Electrochemistry) 56; No.1; the 5-8 page or leaf (1988 " and " Eenichiro Takehara; chemical industry (Chemical Inductries); in January, 1988 concludes in the 52-56 page or leaf and illustrates.

The rechargeable battery of making the working and room temperature of negative electrode with alkali metal has the problems referred to above, and the market of any battery in this class battery is all less than the market of general purpose rechargeable battery.And very the lithium type rechargeable battery market demand of low capacity (1mAh to 3mAh) is also very little.Canadian Moli Encrgy Co., Ltd has released a kind of MoS of using ₂Make positive electrode, make negative electrode with the lithium sheet, LiAsF ₆The rechargeable battery of the electrolytical quite big capacity of type (being higher than 600mAh), this rechargeable battery is at the nickel-cadmium cell that can not be better than same model aspect charge-discharge invertibity, high speed charge and discharge characteristic and the overdischarge characteristic, although its energy density has raising.That is to say that this rechargeable battery lacks the practicality of general purpose.

Find out the reason that causes practical difficulty now, so that the problem of clarification routine techniques.Go wrong under the situation of using alkali metal (particularly making negative electrode with lithium), reason is the person's character that the lithium height is active.Be that lithium and other material react strong.Do not work, charge at battery and when discharging the lithium total surface be with wherein contained electrolyte and impurity react.Therefore, the part or all of lining of electrode surface is stamped one deck and is played the separator that stops the cell reaction effect, and charge and discharge efficient also just reduces.In addition, when charging, can grow dendrite arm inevitably, form and the counterelectrode short circuit, the life-span of battery is shortened.

In order to overcome the above-mentioned problem that causes when elemental lithium is used as negative electrode, the lithium surface must cover the layer of even ion-conducting membrane, and the density of charging current must remain on the low level that can control dendrite arm formation.But, even adopt this means, and under these conditions battery operated, fill-put also and will repeat at every turn, form new lithium surface, because this effect has neither part nor lot in charging and discharge, lithium just slatterns, one of reason that why battery life can not prolong that Here it is.

On the other hand,,, just be controlled to a certain degree with electrolytical effect, but basic problem has nothing different with the problem that causes when using elemental lithium as under the situation of negative electrode at sodium element owing to the high approximately 0.3V of ionization potential of its ionization potential than lithium.In addition, owing to be higher than the reactivity of materials such as lithium and water with the reactivity of material such as water, so difficult treatment can not have practical application.

In view of the foregoing, if alkali metal directly is used as negative electrode, then can form rechargeable battery with good technical ability.Therefore, attempt the use of alkali metal alloy as the high reactivity of modulation alkali metal and the suitable excellent process of control cell reaction.

Lithium and aluminium, tin, plumbous, the referred mistake of the use of the alloy of magnesium or zinc, as at " J.Electrochem.Soc.; 118; No.10; 1547-1549 page or leaf (1971) ", " Journal of Power Sources; 12; 83-144 page or leaf (1984) ", that describes in detail in " B.M.L.Rao, R.W.Francis and H.A.Christopher, I.Electrochem.Soc.; 124; No.10,1490-1492 page or leaf " and " I.R.Owen and W.C Maskell, Solid State Ionics; 13, the 329-334 pages or leaves (1984) " is such.Conclude that in these alloys, it is best that lithium/aluminium alloy is considered to, this is the diffusion velocity maximum because of lithium in aluminium.Most important reason with the alloy replacing alkali metal is, reduced alkali-metal reactivity and avoided generating dendrite arm (as noted earlier) by this reaction with the reaction ， And of control and solvent and impurity.If the use alloy is difficult for the side that chemically reacts just the current potential of alkali-metal electrodeposited coating can be displaced to, can utilize the following current potential of electrodeposited coating.For example, comprise that atomic ratio is that 1/1 the lithium and the alloy of aluminium have than high 0.3 to 0.4V the current potential of elemental lithium current potential.Like this, the reaction of the solvent that just can control and be easy to reduce and dissociate, or the reaction of control and the material that is easy to react with the lithium metallic element.In general, when the current density at electrodeposited coating place was hanged down than big or current potential, the generation of dendrite arm was apparent in view.If the use alloy, this problem just can solve substantially.

But even use alloy, all problems that produces when lithium is used as electrode can not solve fully, can stay some an open question ， And and produce new problem.That is,, can not fundamentally avoid reaction with solvent and impurity even rely on to use alloy to make current potential move 0.3 to 0.4V to the lateral deviation that is difficult for chemically reacting.

For example, the quite frequent organic solvent-carbon propylene that uses even also can heat is moving under than the current potential of the high at least 0.4V of lithium current potential decompose, people know, under situation with ether type solvent (its with the reacting phase of lithium when slightly), impurities can not remove And fully and because the unsteadiness of lithium, solvent can react with lithium gradually.And the difference of alloy and elemental lithium is that attenuation when alloy electrode repeats in charge-discharge can not keep electrode shape at last, and electrode is often broken, makes shorter battery life.In addition, owing to use alloy, compare capacitance density for the capacitance density that obtains to obtain with elemental lithium the time, electrode must possess superfluous extention, promptly must significantly increase with lithium become the complexed metal of alloy and in each charge-discharge circulation time alloy lithium use.In fact released a kind of like this alkali metal rechargeable battery, it comprises lithium alloy or only as the sodium alloy of the active material of electrode, and it has the alkali metal utility ratio of increase, bigger capacitance and good cycle life.

Means as the utility ratio (being power capacity density) that improves the lithium negative electrode, a kind of like this method is disclosed in Japanese unexamined patent (publication number 48-24302), Japanese unexamined patent (publication number 59-14264) and Japanese unexamined (publication number 62-140358), wherein, electrode surface areas relies on the method that elemental lithium or aluminium alloy are mixed with material with carbon element to be increased (as noted earlier).A kind of method is disclosed in Japanese unexamined patent (publication number 59-157973), wherein, surperficial processed or covering one deck material with carbon element of lithium or lithium alloy.Really, if having the carbon black of specific surface area or other dispersion of materials in negative electrode, then the actual effective area of negative electrode is increased.But reactivity has but increased, and also becomes obvious with the side effect of electrolyte etc.Exactly, carbon black etc. can be used as the active material of electrode, have only when the electrode surface covering carbon material, could obtain to improve charge-discharge efficient or keep the constant effect of performance.

Disclose in Japanese unexamined patent (publication number 60-26351), Japanese unexamined patent (publication number 61-245474) and Japanese unexamined patent (publication number 62-140358) the trial of a species complex as the active material of electrode, this complex comprises a kind of so-called conducting polymer (substituting aforementioned material with carbon element) and a kind of alkali metal or alkali metal alloy that has a conjugated double bond on its main chain.Under the situation of using lithium or lithium alloy, like that at composite material, can increase electrode surface areas, but can cause undesirable side effects as described above with material with carbon element.

About above-mentioned trial, only when alkali metal alloy is sodium alloy, promptly only when using Japanese unexamined patent to disclose in 61-245474 number disclosed sodium alloy, can effectively obtain improving ， And and can bringing up to real standard to the capacitance density of negative electrode of every index.Its reason is because the reactivity of sodium metal alloy is lower than the reactivity of lithium, if selected suitable electrolyte then can be controlled nearly all side effect, if sodium metal alloy and conducting polymer are combined, then can increase effective surface area, and don't cause side effect.

The intrinsic in essence lower conductance of conducting polymer, conducting polymer considers it is electric insulation from the angle of cell reaction, only it is mixed with alkali metal or other impurity.Therefore, if unadulterated conducting polymer only is dispersed in the electrode, then electrode only can obtain the effect of liquid barrier (liguid-retaining).This doping is just had an effect naturally when complex is immersed in the electrolyte, and this is because between conducting polymer and alkali metal alloy potential difference is arranged, but speed of action is lower.The current potential of negative electrode causes and mixes and undope during according to the battery charge and discharge, but conducting polymer always can evenly not mix.So conducting polymer must be mixed with alkali metal before it forms complex.Or mix with electrochemical means or with chemical mode, focus on the industrial problems, consider that from economic angle this initial doping is not selected the superior.In addition, as above pointing out, when if conductive doped polymer is used to form complex, because should be used as the part alkali metal ion of the active material of charge and discharge is inherently caught by conducting polymer, so need excessive alkali metal ion, thereby the capacitance density of electrode reduces.The doping of conducting polymer changes according to electrode potential, if doping is little, then conductivity reduces.So the polymer after mixing is during as the electrode of battery, by as the conducting polymer after the doping of composite material compositions, the active electrode current potential just narrows down, and available battery voltage range is subjected to bigger restriction.

The heavy-duty battery that only relies on the composition improve negative electrode not produce to have high-energy-density and long circulation life.Obviously, these improvement must combine with suitable positive electrode material and suitable electrolyte.For example, using TiS ₂Or MoS ₂Do under the situation of positive electrode material, can obtain cell voltage and be up to 2.5V, active material of available lithium type or the active material of sodium type are made negative electrode, but can not obtain to have the heavy-duty battery of high-energy-density.

Past attempts proposes to make positive electrode material with sodium-cobalt/cobalt oxide, as illustrated like that in " Journal of Solid Chemistry, 6, the 532-537 pages or leaves (1973) ", can provide a kind of good positive electrode.But, also untappedly that kind go out for introducing or discharging the effective negative electrode material of sodium ion, also not test (N.T.) goes out to be used for the electrolyte of battery.Therefore, only rely on and use the carbon propylene that is not suitable for sodium type negative electrode to come positive electrode is estimated, the battery that includes this positive electrode can not be provided.

Only with carbon propylene or carbon ethene or with the situation of another kind of solvent form of mixtures together as electrolyte solvent under; if negative electrode is made of the lithium metal with smooth surface; then surface area is less; less with the product amount of solvent reaction, and this product can play diaphragm.But this solvent is with to have the particular surface that reduces violent so that form the alkali metal negative electrode reaction of high-capacitance type battery, and this solvent can not use at all in this case.But, under the situation of lithium metal composite material electrode, have enough conductivity and be applicable to that the solvent of positive electrode is also untapped.

In brief, even at present, the problems referred to above also carry over and are not solved, and also untappedly go out a kind ofly to have high-energy-density, long circulation life and can carry out industrial alkali metal rechargeable battery with low cost.

Be conceived to address the above problem, the inventor has now found the good combination of the active material composition of a kind of battery.

Or rather, according to the present invention, a kind of rechargeable battery can be provided, it includes a positive electrode, a negative electrode and a kind of not aqueous electrolyte, wherein, positive electrode includes the sodium-cobalt/cobalt oxide as main component, and negative electrode is made of complex, this complex includes a kind of sodium alloy, a kind of material with carbon element and a kind of binding agent, and aqueous electrolyte is not made of a kind of sodium salt and a kind of ether compound.

Fig. 1 is the cross sectional view of explanation Coin-shaped battery;

Fig. 2 be explanation in example 1 the curve of the battery that obtains change in voltage when the 5th charge and discharge cycle;

Fig. 3 be explanation when charge and discharge cycle test each circulate and discharge capacity between the curve that concerns;

Fig. 4 be explanation in example 2 the curve of the battery that obtains change in voltage when the 5th charge and discharge cycle;

Fig. 5 be explanation when charge and discharge cycle test each circulate and discharge capacity between the curve that concerns;

Fig. 6 be explanation in example 5 institute's battery that obtains during at loop test each circulate and discharge capacity between the curve that concerns;

Fig. 7 is explanation curve that concerns between battery discharge current value and the discharge capacity that obtains in example 6;

Fig. 8 be explanation in example 7 the curve that concerns between the battery charge current value that obtains and the discharge capacity;

Fig. 9 be explanation when discharge temperature and discharge capacity between the curve that concerns.

In the rechargeable battery with positive electrode (being consisted of by lithium-cobalt/cobalt oxide) of the present invention, the current potential of the minimizing oxidation of sodium-cobalt/cobalt oxide is compared with the current potential of the minimizing oxidation of sodium in a suitable scope, be approximately 3V(in fact, amount according to sodium in sodium-cobalt/cobalt oxide, current potential is in 2 to 4V scope), sodium-cobalt/cobalt oxide adsorbs in electrochemical mode and discharges sodium ion having in good reversible situation. Therefore, based on active material, capacitance density is high. Sodium-cobalt/cobalt oxide has high conductivity in essence, substantially need not use conductive agent. Only when the bulk density of control electrode, just regulate electrolytical injection rate, the interfacial area between electrode and the electrolyte increases, and must use conductive agent.

Carbon black is applicable to conductive agent, and preferably conductive agent adds with binding agent, in order to make the amount of carbon black in electrode be not more than 7% weight, the amount of binding agent is not more than 6% weight. In this case, the electrode with good flexibility can obtain from this combination, can at full speed carry out charge and discharge, and the capacitance density of electrode per unit volume can increase. At the positive electrode material that has low electric conductivity with other (such as ν-type MnO₂) when the electrode, if cause electrode deformation and make minimizings that contact with conductive agent by charge and discharge, especially when carrying out deep discharge, then can not carry out reposefully charge and discharge successively, Efficiency Decreasing appears, shortening electrode life. On the contrary, in the situation of sodium-cadmium oxide, because electric conductivity is high, even by deep discharge the change in volume of active material also can not given rise to trouble. And whole electrode participates in electrode reaction reposefully, and electrode is with efficiency operation. In the crystal structure of sodium-cobalt/cobalt oxide, ν-type structure is best suited for battery electrode, and this structure is illustrated as P in " Journal of Solid State Chemistry, 6, the 532-537 pages or leaves (1973) "₂Phase. In the sodium-cobalt/cobalt oxide of ν-type structure, even if crystal structure sodium ion be adsorbed with electrochemical means and situation about discharging under also can be the changing on a large scale of lithium content, so this structure has good invertibity.

But, only make positive electrode with kind electrode, the battery that can not produce as good fit, needs suitable negative electrode and suitable electrolyte.

Therefore, the inventor seeks a kind of component material ， And that has a superperformance as the active material of negative electrode and finds a kind of sodium alloy complex with superperformance that the lithium alloy complex do not had.

Sodium can form alloy with many metals, and in these alloys, sodium/lead alloy and sodium/ashbury metal are better as electrode material, and this is because the metal (being lead or tin) that cooperates can form alloy on the wide region of sodium atom ratio.Or rather, under the situation of sodium/lead, alloy can form in the scope of sodium/lead atom ratio of from 95/5 to 2/98, and under the situation of sodium/tin, alloy can form in the scope of sodium/tin atom ratio of from 100/0 to 5/95.And, sodium and the alloy that is selected from least a metal in plumbous and the tin are being used as under the situation of electrode, the atomic ratio of sodium and complexed metal can be set according to the fixed electrode potential of desire, and on the contrary, electrode potential is recently set by atom.Therefore, can control composition at an easy rate in electrochemical mode.Moreover under the situation of this alloy, sodium changes in narrow potential range (0.5V according to appointment) than cardinal principle with the composition of complexed metal.Therefore, when alloy is used as electrode, be in the current potential uniformity that going up of capacitance can keep good on a large scale at the charge or discharge film.

But, as noted like that, can not bring advantage to sodium alloy as Dian Ji And simply.In order to use sodium alloy in the practicality satisfactorily, must in electrode, form and to maintain an amount of electrolytical space, interface between active material and the electrolyte in the necessary increase electrode is so that electrode reaction can need not at full speed carried out under the actual superpotential condition.In this case, entire electrode can participate in electrode reaction equably, can control that overcharge in the part or the generation of overdischarge, when the control dendrite arm forms, can carry out the high speed charge and discharge.The material that interface between active material and the electrolyte is increased as far as possible and can suitably control the electrode bulk density stable with respect to electrode is a material with carbon element, as carbon black or graphite.Because material with carbon element has high conductivity, so material with carbon element also plays a part conductive adjuvant, so that advance electrode reaction rapidly.And material with carbon element is highly stable with respect to electrolyte etc.Carbon black has very large specific surface area and high-voidage ratio.Graphite shows certain elasticity deformation, although its specific surface area is less than the surface area of carbon black.Therefore, if graphite is mixed electrode, the then expansion and the contraction that cause of the electrode reaction of may command by the active material of electrode can be kept electrode shape.In addition, the expansion deformation that can cause the infiltration by electrolyte etc. controls to reduced levels.

The kind and the preparation method that are used to form the material with carbon element of composite body do not have particular restriction, no matter kind and preparation method how, can use any material with carbon element.For example, available native graphite, Delanium and the hot tearing graphite that relies on the vapor phase method preparation is as described graphite, and available acetylene black, heat are black, furnace black and activated carbon be as described carbon black.But, consider from the angle of capacitance density, preferably may use the material with carbon element that shows maximum efficiency slightly.In this case, preferably only make required electrode shape as described material with carbon element ， And with binding agent with carbon black.In addition, under the important situation of the certain Dian Rong of needs Liang And and invertibity, best combination is used carbon black with big specific surface area and the acetylene black with less specific surface area, use the mixture of graphite fibre or carbon fiber or carbon black and graphite, dependence utilizes binding agent to form, to obtain required electrode shape.In brief, no matter available any material with carbon element, and its kind and preparation method can be used alone material with carbon element or with the material with carbon element of two or more mixtures of material form.

As a kind of composition of negative electrode, be enough to provide required electrode shape under preferably can the use amount less situation of binding agent, in general, used binding agent and electrode and electrolyte can not react.Common situation is that the operating position of polyethylene or polyacrylic fiber or powder is this fiber or powder to be distributed in the electrode fully heating then, fusing.The inventor has found a kind of olefinic copolymer rubber, as ethylene/propylene rubber (EPR), ethylene/butylene rubber (EPDM), binding agent as negative electrode material is the most effective, the relative solvent for use of the special Zhi Man  PDM of EPDM is stable, promptly, as ether compound, EPDM has stronger viscosity, is used to obtain the required amount of enough pole strengths and can reduces to half that is less than polyethylene or polypropylene consumption.

In order to make the high-performance storage battery, need a kind of relative two electrolyte that high conductivity is all stablized and had to electrode, also be like this even if reserved under the situation of best composition and shape at positive and negative electrode.As noted earlier like that, can not be with the carbonate with high polarity (as propylene carbonate Propylcne Carbonate), the electrolyte that positive and negative relatively two electrodes have good stability and have a high conductivity is a dependence a kind of Na salt (NaPF especially ₄Or NaBF ₄) be dissolved into formed system in a kind of ether compound.

Available various ether compound is as battery solvent, they for example comprise: 1,2-dimethoxy-ethane, 1,1-dimethoxy-ethane, oxolane, 2-methyltetrahydrofuran (2-methyltetrehydrofuran), 1,3-dioxolanes, 4-methyl isophthalic acid, 3-dioxolanes, anisole, trifluoromethyl anisole (trifluoromethylanisole), diox (dioxane) and dialkyl ethers macrogol ester (polyethylene glycol dialkyl ethers).Consider the stability and the conductivity of electrolyte form, dialkyl ethers glycol ester (polyglycol dialkyl etheis) that the most handy following formula (1) is expressed and composition thereof is made solvent:

R ¹-O-（C _mH _2mO） _n-R ²（1）

R wherein ¹And R ²Representative has the alkyl of 1-8 carbon atom respectively, and n is from 1 to 8 integer, and m is from 2 to 3 integer.

At room temperature have high conductivity and and electrolyte with good stability can rely on a NaPF ₆Or NaBF ₄Be dissolved into 1, in the 2-dimethoxy ethene and obtain.As one even have goodish conductivity when low temperature (as being lower than-20 ℃ temperature), have to control to and be lower than separately 1, the easy-to-handle single system of Qi Ya And of 2-dimethoxy-ethane air pressure preferably relies on NaPF ₆Or NaBF ₄The system that is dissolved in three water diethyl acetal dimethyl ether or the 1-ethyoxyl-second-Ethyl Methyl Ether and obtains and relying on NaPF ₆Or NaBF ₄Be dissolved into by 1, in the admixture solvent that 2-dimethoxy ethane and polyethylene glycol dialkyl group ether (by formula (1) expression) constitute and the system that obtains.Mixed solvent preferably 1,2-dimethoxy-ethane and three water three dimethylamino ethanol ethers, three, three ethanol diethyl ether, three the contract mixed solvent of tetraethoxide diethyl ether of tetraglyme or three that contracts that contracts that contracts.Found that if aforesaid ether compound is sneaked into 1 with from 2/1 to 1/20 volume ratio the 2-dimethoxy-ethane then can improve low-temperature characteristics greatly.Conductance is shown in Table 1 when room temperature and-20 ℃.

Table 1

Electrolyte conductivity

（ms/cm）

24℃????-20℃

1M NaPF ₆/TrEGDME - -

1M NaPF ₆/TrEGDME+DME（1∶1） 5.8 0.6

1M NaPF ₆/TrEGDME+DME（1∶3） 9.8 5.1

1M NaPF ₆/TrEGDME+DME（1∶5.8） 10.9 5.7

1M NaPF ₆/TrEGDME+DME（1∶9） 10.8 5.3

1M NaPF ₆/TeEGDME+DME（1∶3） 9.8 5.3

1M NaPF ₆/TeEGDME+DME（1∶9） 12.1 6.2

1M NaPF ₆/TrEGDME+DME（1∶19） 13.2 4.8

1M NaPF ₆/TeEGDEE+DME（1∶3） 8.6 4.6

1M NaPF ₆/TeEGDEE+DME（1∶9） 11.5 4.1

1M NaPF ₆/TeEGDEE+DME（1∶19） 12.6 2.9

1M NaPF ₆/DME 15.2 0.9

Note, in the table

DME:1, the 2-dimethoxy-ethane

TrEGDME: three water, the three dimethylamino ethanol ethers that contract

TeEGME: the three water tetraglyme that contracts

TeEGDEE: the three water tetraethoxide diethyl ether that contracts

The best of present description positive and negative electrode component is the preparation method when.

Better with sodium-cobalt/cobalt oxide as the active material of positive electrode with ν-type structure, and it is good especially to have a sodium-cobalt/cobalt oxide of ν-type structure of at least 70% weight.Its reason is that this structure electrochemical of going up on a large scale of sodium content is stablized in ν type sodium-cobalt/cobalt oxide.When using oxide, sodium/cobalt atom ratio does not have particular restriction, but when oxide with the sodium/cobalt atom from 0.65/1.0 to 0.90/1.0 when synthetic, can obtain good result.Finish the synthetic of ν-type sodium-cobalt/cobalt oxide according to disclosed method in " Journel of Solid State Chemistry, 6, the 532-537 pages or leaves (1973) ".In the shaping of electrode, because sodium-cobalt/cobalt oxide has good electrical conductivity, so the additional conductive assistant is not absolutely necessary.Under the situation of coin shape or plate shape electrode because after being shaped, do not need to make electrode bend around or deformation, so flexibility need not arranged.Therefore, only rely on powdery sodium-cobalt/cobalt oxide is compression molded into ball, plate etc., just can be enough to keep electrode function.Under the situation of cylindrical battery, although sodium-cobalt/cobalt oxide has certain bonding characteristic, because of when electrode is inserted cylindrical tank, needing higher flexibility, so often need higher flexibility.Therefore, need sometimes to rely on binding agent that flexibility is provided.But when using binding agent,,, will reduce the function of active material if binding agent only mixes in sodium-cobalt/cobalt oxide powder because binding agent has electrical insulation characteristics.So, must be used in combination carbon black with liquid injection properties.On the contrary, when relying on additional carbon black to come the control electrode bulk density, the essential binding agent that adds, this and electrode shape have nothing to do.

As binding agent, the most handy fluorocarbon resin (as polytetrafluoroethylene) or olefin-copolymerization (olefin copolymer) rubber (as EPDM).Its reason is that this binding agent is stable in electrode normal working voltage scope, and presents bond effect preferably, and this binding agent can provide the electrode with required form and improved flexibility under the little situation of consumption.But, as the binding agent that mixes and amount of carbon blacks are too big, capacitance density can reduce.Preferably the incorporation of carbon black is not more than 7% weight, and the incorporation of binding agent is not more than 6% weight.

Under the situation of using adhesive, if make sodium-cobalt/cobalt oxide surface be covered with adhesive as point out the front, then the electrode activity descends.Therefore, preferably adopt following method to form electrode: at first with adhesive and a kind of organic solvent swollen simultaneously.Or be dissolved in this solvent, carbon black is combined with adhesive, directly mixture is mixed with sodium-cobalt/cobalt oxide, or after organic solvent is got rid of, do above-mentioned mixing from mixture, then this mixture is molded as desirable electrode shape.Preferably select for use cyclohexane, benzene, dimethylbenzene and toluene to make the solvent of swollen and dissolved adhesive.The bulk density of positive electrode (being not counted in current-collector) is preferably 2.3 to 3.5 gram/cm ³

In battery of the present invention, negative electrode must be made up of a complex that comprises sodium alloy, material with carbon element and an adhesive.In order to obtain high efficiency high electrode performance, this complex preferably comprises the sodium alloy of at least 80% weight, the adhesive of the material with carbon element of 3～20% weight and 1～8% weight.Do not constitute if do not satisfy this composition, electrode performance then descends.For example, if sodium alloy weight is less than 80%, then capacitance density is undesirable, if material with carbon element weight is less than 3%, the suitable bulk density of control electrode then, and in the circulation some shortcomings will appear in early days, as cracked, dendrite forms and the electrode utility ratio reduces or the like.If material with carbon element weight surpasses 20%, bulk density reduces, and pole strength also reduces, and the generation shortcoming relevant with capacitance density and cyclophysis.If binder wt less than 1%, then can not obtain enough pole strength, and in early days can be chipping.If binder wt surpasses 8%, then resistance is excessive in the electrode, can not carry out electrode reaction reposefully, also can not produce high capacitance.

The bulk density of negative electrode (being not counted in current-collector) is 1.7 to 2.5 gram/cm preferably ³

The preparation negative electrode preferably adopts the similarity method of above-mentioned preparation positive electrode.Specifically, can adopt following method: adhesive and a kind of organic solvent be swollen simultaneously, or be dissolved in this solvent, carbon black (optional graphite powder) is mixed effectively with adhesive, directly or after from this mixture, getting rid of solvent this mixture is mixed with the sodium alloy powder, then mixture is molded as desired electrode shape.Yet the preparation method is not limited thereto.Can adopt polyethylene or polypropylene fibre or powder to make adhesive, but the most handy EPPM(ethylene/propylene rubber) because just can obtain high binding effect on a small quantity, and electrode or electrolyte reaction are also low.Preferably adopt cyclohexane, benzene, dimethylbenzene and toluene to do adhesive solvent.

Above-mentioned positive electrode, negative electrode and electrolyte are combined, can prepare a high characteristic battery, can not obtain this specific character and use them separately or it is used in combination with other material with low cost.

Be described in detail rechargeable battery of the present invention below with reference to following examples.These embodiment never limit the scope of the invention.

Example 1:

In a mortar, the Na of 8.2 grams ₂O ₂Co with 24.1 grams ₃O ₄Ground and mixed, stirred a few minutes with high speed agitator.This mixture is sent into an electric furnace.Elevated temperature progressively in atmospheric pressure, calcining is 2 hours in the time of 550 ℃.Mixing temperature is raised to 740 ℃ then, and in this temperature, the goods of calcining keep 15 hours with synthetic sodium-cobalt/cobalt oxide.When analyzing the synthetic products of natural cooling, confirm that this synthetic products is made up of γ type sodium-cobalt/cobalt oxide basically fully with X-ray diffractometer.When determining the Na/Co atom rate of synthetic products with the ICP radioactive method, find that it equals 0.705/1.00.

Synthetic products is sufficiently ground so that obtain the powder of diameter less than 100mesh.Claim 250 gram dust samplings, and with the sheet moulding press with its sheet that is molded into diameter 15mm, a stainless steel expanded metal current-collector is contained in the sheet.Adjust thickness of electrode, make not comprise that expanded metal equals 3.1g/cm in interior electrode bulk density ³Zhi Bei electrode is as positive electrode like this.

Manufacture negative electrode with following method.At first, the sodium/lead atom rate with 2.7/1.0 in the argon gas stove is manufactured sodium lead alloy, and this alloy is sent into a ball container in the argon gas, and at this, the content of water and oxygen is controlled to such an extent that be lower than several ppm.Use a stainless steel mortar and a stainless steel bar to grind alloy, particle diameter is reduced to below the 100mesh.Wash carbon black (registered trade mark that is provided by Showa-Cabot is Black Pearl 2ooo) with acetone and ethanol, in 500 ℃ temperature, reduce pressure then and heat-treat.Then, in the carbon black of handling like this of 102 grams, add 2.5 grams and be dissolved in 60 ℃ of EPDM(JSR-EP579 in the dimethylbenzene, Japan Synthetic Rubber provides), stir the mixture effectively then, under 80 ℃ of decompression situations dry 1 hour to get rid of dimethylbenzene.Afterwards, claim mixture and above-mentioned alloy powder that 10.0 grams obtain, it is fully mixed, with a high speed agitator it is mixed again with a mortar and rod.Afterwards, claiming the 130mg blend sample, is the sheet of diameter 15mm with the sheet moulding press with its mold pressing, and a nickel expanded metal current-collector is included in the sheet, and the thickness of trimmer makes not comprise that expanded metal is 2.1g/cm in interior electrode bulk density ²

The electrode of so manufacturing is as negative pole.The weight rate of Na alloy/carbon black/EPDM is 87/10.4/2.6.

Electrolytical being prepared as follows: from 1,2 Olimethoxethane to NaPF ₆Do tertiary recrystallization, 60 ℃ of drying under reduced pressure sodium salts, it is that 1.0 mol are among 1,2 dimethoxy-ethane that distillation is purified, with Na Hg eliminating a small amount of impurity that dry sodium salt is dissolved in concentration.

Above-mentioned part is assembled into a Coin-shape cell, and its diameter is 20mm, and thickness is 1.6mm, as following shown in Figure 1.

Injected electrolytical negative pole 6 in advance among stretching, extension shape metal collector 2 is placed into a container, injected electrolytical microporous polypropylene membrane 4 in advance and the non-woven cloth of polypropylene places on the negative pole 6, the positive electrode 1 that has injected positive electrolyte in advance is placed on it again with stretching shape metal collector 2.Then, from top supply electrolyte, make system sufficiently inject electrolyte.Then, cover container with a loam cake, to the container ca(u)lk, such battery has just installed with ca(u)lker.Reference number 5 is represented insulating bag.

The cell voltage that has just installed is 2.50V.When determining that with 2.5mA current value discharges with course of discharge, the discharge capacity before cell voltage drops to 1.7V equals 10.6mAh.After the discharge, the open circuit that forms 30 minutes is so that static battery.Charge with the constant current of 2.5mA then, arrive 3.2V up to cell voltage.

After charging finishes, to battery do 30 minutes static, discharge with same current value then, drop to 1.7V until cell voltage.Continuous like this carrying out of discharge-charge cycle test all has 30 minute quiescent time behind each charging and discharging, so that check discharge capacity and cycle time.After the 25th the cycle charging, form open circuit, battery was kept 1 month down at 25 ℃, under the similarity condition that period measuring adopts, check discharge capacity, to determine self-discharge rate.After the self discharge test, carry out period measuring.

Fig. 2 represents that the 5th cycle charging/discharging voltage changes, and discharge capacity is 18.0mAh.Relation between each cycle and discharge capacity sees that Fig. 3-(a), maximum discharge capacity is 19.0mAh, and it was 252 cycles that discharge capacity reduces to 1/2 cycle lie.This battery purpose self-discharge rate in the time of 25 ℃ is 3.2%.

Example 2:

In a mortar, 14.8 Na ₂The Co of Co and 26.8 grams ₃O ₄Fully ground, and do the mixing of a few minutes with a high speed agitator and stir, mixture is inserted in the electric furnace, and the speed with 3 ℃/minute in oxygen rises to 750 ℃ to temperature, keeps 15 hours in this temperature, so that synthetic sodium-cobalt/cobalt oxide.When analyzing the synthetic products of natural cooling with X-ray diffractometer, confirm that this synthetic products mainly is made up of γ type sodium-cobalt/cobalt oxide, be considered as the rapid cobalt/cobalt oxide composition in Luan on a small quantity and present.According to the diffraction maximum rate, think that synthetic products comprises 3% β type oxide and 97% γ type oxide.When determining the Na/Co ratio, find that it equals 0.82 with the ICP radioactive method.Synthetic products is fully ground powder less than 100mesh, claim the powder of 195mg, and it is molded into the sheet of diameter 15mm with the sheet moulding press, a stainless steel expanded metal current-collector is included in wherein.Adjust thickness of electrode, make that not comprise expanded metal be 3.1g/cm in interior electrode bulk density ³The electrode of so making is as positive electrode.

Prepare negative electrode with the following methods.

Atom ratio with 2.25/1.0 in the argon gas stove is manufactured sodium lead alloy, and in argon gas it is sent into a spherical volume, and it is fully ground with a stainless steel mortar and a stainless steel bar, makes diameter be not more than 100mesh.

The 2.5g EPDM that uses in the dissolving example 1 in 60 ℃ the dimethylbenzene that is heated at 50cc.The graphite powder (washed with acetone and ethanol, and 500 ℃ of heat treatments being done in decompression) that the Showa Denko of Showa-Cabot carbon black used in the example 1 of 6.5 grams and 3.5 grams is provided adds in the above-mentioned solvent, and fully stirs.Under 880 ℃ of situations of decompression, mixture is carried out dried to get rid of dimethylbenzene.During when use cyclohexane, benzene or toluene and without dimethylbenzene, can similarly use the solvent of formation, but on the apperance that is used to dissolve difference be arranged equably.Have been found that the most handy dimethylbenzene and cyclohexane are made solvent in these varsols, they can wherein particularly should select dimethylbenzene for use to dissolve EPDM equably in a small amount.

Afterwards, claim 10 grams dry mixture and the above-mentioned alloy powder of 68.0 grams, with a mortar and fully mixing of rod, get this mixture of 160mg, with its sheet that is pressed into diameter 15mm, a nickel expanded metal current-collector is included in wherein with a sheet moulding press.

Adjust this thickness of electrode, make not comprise that expanded metal is 2.2g/cm in interior electrode bridge density ³The electrode of so manufacturing is a negative electrode.In this negative electrode, sodium alloy/material with carbon element/EPDM weight rate is 87.2/10.3/2.6.Use with example 1 in the identical electrolyte of electrolyte.

Mode in the use-case 1 is assembled Coin-shape cell shown in Figure 1.

Firm ready-made cell voltage is 2.48V.When along course of discharge during with the definite current value discharge of 2.5mA, the discharge capacity before cell voltage is reduced to 1.70V is 10.3mAh.

Get 30 minutes quiescent time after the discharge, with same current value charging, arrive 3.7V then until cell voltage.

Get 30 minutes static pressure time after the charging, discharge drops to 1.7V until cell voltage then.Repeat to discharge and recharge with the same manner, when the 50th cycle, measure self-discharge rate.

In above-mentioned test, the charging voltage that Fig. 4 showed for the 5th cycle changes, and discharge capacity equals 24.0mAh.Relation between each cycle and discharge capacity is shown in Fig. 5-(a).Maximum discharge capacity is 24.7mAh, and it is 162 cycles that capacity is reduced to 1/2 cycle lie.One month self-discharge rate in the time of 25 ℃ is 49%.

Example 3:

Use-case 1 described mode is from the sodium-cobalt/cobalt oxide of the synthetic about 100% γ type structural content of same parent material.Synthetic products is fully ground, to obtain the powder that diameter is not more than 100mesh.

6 gram carbon blacks and 2 gram EPDM all in the example 1 are dissolved in respectively in the dimethylbenzene, and mixture is fully stirred, and does dried when decompression, so that eliminating dimethylbenzene, afterwards, the carbon black of 0.400 gram and EPDM mixture are added in the sodium cobalt/cobalt oxide of 9.600 grams, mix with high speed agitator.Afterwards, claim the 230mg mixture, with its sheet that is pressed into diameter 15mm, an expanded metal current-collector is included in wherein with a sheet moulding press.

Adjust thickness of electrode, make not comprise that expanded metal is 2.9g/cm in interior electrode bulk density ³The electrode of so making is as positive electrode.

Negative electrode is manufactured by following mode.

With example 1 in the sodium/lead alloy manufactured of same way as and carbon black (Sho-Black N 110 registered trade marks that are dissolved in the dimethylbenzene, Showa-Cabot produces) and EPDM(JSR-EP25X, Japan Synthetic Rubber production) mixture mixes mutually, makes sodium alloy/carbon black/EPDM weight ratio equal 88/9.5/2.5.

Claim 125mg this mixture then, with its sheet that is pressed into diameter 15mm, a nickel expanded metal current-collector is included in wherein with a sheet moulding press.Adjust thickness of electrode, make not comprise that expanded metal equals 2.1g/cm in interior electrode bulk density ³The electrode of making like this is a negative electrode.Adopt with example 1 in identical electrolyte.

With Coin-shape cell of the same manner assembling in the example 1.The cell voltage that has just installed is 2.51V.When definite discharging current of course of discharge is 2.5mA red third constellations Miao mushroom to support the discharge capacity before the .70V be 10.0mAh.Get 30 minute quiescent time after the discharge, with same current value charging, arrive 3.2V again until voltage.Get 30 minute quiescent time after the charging, again with same current discharge.Afterwards, condition described in the use-case 1 is carried out battery performance test.

Relation between each cycle and discharge capacity is shown in Fig. 3-(b), and maximum discharge capacity is 17.1mAh, and it was 258 cycles that capacity is reduced to 1/2 cycle lie.One month self-discharge of battery rate is 3.0% during 25 ℃ of temperature.

Example 4:

Manufacture a positive electrode with the method in the example 3, but electrode weight becomes 182mg.Manufacture negative electrode with the method in the example 2, but electrode weight becomes 160mg.With concentration among the DME is the Na β F of 1mole/l ₄Solution is done electrolyte.

With above-mentioned electrode and electrolyte assembling Coin-shape cell shown in Figure 1.Use-case 2 described method test battery performances.Relation is shown in Fig. 5-(b) between each cycle and discharge capacity, and maximum discharge capacity is 24.0mAh, and cycle lie was 173 cycles.One month self-discharge of battery rate is 4.5% in the time of 25 ℃.

Example 5:

Sodium-the cobalt/cobalt oxide of method preparation mixes with polytetrafluoroethylene (it intersperses among in the cyclohexane as solvent) and the carbon black that Daiki Kogyo produces in the use-case 1, and the weight ratio that makes sodium-cobalt/cobalt oxide/polytetrafluoroethylene/carbon black is 92/5.5/2.5.Decompression is to the mixture dried, with the 215mg drying the mixture mold pressing be the electrode of diameter 15mm, make that not contain current-collector be 2.70g/cm in interior electrode bulk density ³The electrode of so manufacturing is a positive electrode.

Use with example 1 in negative electrode negative electrode and the electrolyte the same with electrolyte.Assemble Coin-shape cell shown in Figure 1 and detect its battery performance.The cell voltage that has just installed is 2.51V.Along putting to determine the constant current discharge with 2.5mA, be 1.80V until voltage, the electric weight that can be discharged is 8.5mAh.After static 30 minutes, charge, be raised to 2.75V until voltage with same electric current.Static 30 minutes,, drop to 1.80V until voltage with same current discharge.So, carry out charge-discharge test repeatedly.In the 25th cycle, make the battery open circuit, in the time of 25 ℃, keep January, check self-discharge rate then.

Relation as shown in Figure 6 between each cycle and discharge capacity.Maximum pd quantity is 11.0mAh, and the cycle lie that discharge capacity drops to 7mAh was 699 cycles.One month self-discharge of battery rate is 2.5% in the time of 25 ℃.

Example 6:

Identical battery in assembling and the example 3 tests to discharge and recharge with following method.Begin the 10th stable cycle in discharge capacity, the 2.5mA discharging current in front cycle is become 5mA, in the 12nd cycle, discharging current becomes 10mA.In the 14th cycle, discharging current becomes 15mA, and in the 16th cycle, discharging current becomes 20mA, and in the 18th, 19 cycle, discharging current becomes 1mA.Each cycle is all used 2.5mA constant charging current.Really concern between discharge current value and the discharge capacity.Found that if discharge capacity is 100% during 2.5mA then discharge capacity is 90% during 1 year mA.Therefore, confirmed that this battery is suitable for high rate discharge, the gained result as shown in Figure 7.

Example 7:

The battery that assembling is identical with example 3, electrical testing in the following manner charges.Begin the 10th stable cycle in discharge capacity, the 2.5mA charging current that the front cycle adopts becomes 5mA, and in the 12nd cycle, charging current becomes 10mA, becomes 15mA in the 14th cycle, becomes 20mA in the 16th cycle, becomes 1mA in the 18th, 19 cycles.Each cycle is all used the constant discharging current of 2.5mA.Check the relation between charging current value and discharge capacity.

Found that the discharge capacity that obtains during then with the 15mA current charges is 80% if the discharge capacity that obtains during with the 2.5mA current charges is 100%.Confirmed that battery is suitable for charging at a high speed, the gained result as shown in Figure 8.

Example 8:

The battery that assembling is identical with example 3.After discharge capacity begins stable the 10th cycle charging, under different temperatures, discharge with 2.5mA constant electric current.Charging at room temperature.The result is shown in Fig. 9-(a).Dissolving NapF when concentration is as 1mole/l in using DME ₆In the electrolytical system that forms, the low temperature discharge capacity is less than the room temperature discharge capacity.

Example 9:

The mode of use-case 3 is assembled a battery, but the electrolyte that uses is with 1mole/l concentration dissolving NaPF in a kind of mixed solvent (comprise DME and tetraethylene glycol ethane ether, volume ratio is 3/1) ₆Form, and do not make the electrolyte of use-case 3.

Way in the use-case 3 is done and is discharged and recharged and the self discharge test.Have been found that maximum discharge capacity is 16.4mAh, it was 422 cycles that capacity reduces to 1/2 cycle lie.One month self-discharge of battery rate is 2.4% in the time of 25 ℃.

Example 10:

The battery that assembling is identical with example 9, inspection discharge capacity temperature dependency under the experimental condition of example 8.The result is shown in Fig. 9-(b).Can find out from this figure, even when low temperature (20 ℃), discharge capacity during also greater than room temperature discharge capacity 50%.

Example 11-20:

In the battery system in example 3, change the kind of electrolyte solvent, check room temperature (25 ℃) maximum discharge capacity, cycle lie, self-discharge rate and low temperature (20 ℃) discharge capacity.The result is as shown in table 2.The voltage cut-off scope is 1.7V-3.2V.Current value is 2.5mA, does a purpose self discharge test in the time of 25 ℃.

Example 21:

Make positive electrode and electrolyte in the use-case 1, manufacture negative electrode as follows.

In the argon gas stove, the alloy that comprises sodium and tin (atomic ratio is 2.5/1.0) is fully ground to form particle diameter less than 100mesh.Carbon black of using in the example 1 and EPDM are added among the alloy of grinding, and making weight alloy is 88%, and carbon black is 9.5%, and EPDM is 2.5%.Mixing in the use-case 2 and die pressing are manufactured the electrode of 80mg, and making the electrode bulk density is 1.3g/cm ³The electrode of so manufacturing is as negative electrode.

Assemble Coin-shape cell shown in Figure 1, use the method test electrode performance identical with example 1.Maximum discharge capacity is 16.1mAh, and cycle life is 299 circulations, and self-discharge rate is 3.8%.

Example 22:

The method of use-case 3 is manufactured positive electrode, becomes 200mg but the mixed weight of sodium-cobalt/cobalt oxide/carbon black/EPDM ratio becomes 86/10/4 electrode weight, and bulk density is 2.0g/cm ³Method in the use-case 3 is manufactured negative electrode, but electrode weight becomes 100mg, and the method for use-case 3 is a battery with this positive and negative electrode dress.

Because the positive electrode bulk density of this battery is low, the amount in the battery of active matter quality ratio 3 is few.With the method test battery performance identical with example 3.Found that maximum discharge capacity is 11.9mAh, cycle lie was 362 cycles, and self-discharge rate is 3.5%.

Example 23:

Manufacture negative electrode with the method identical, but the mixed weight of alloy carbon black/EPDM ratio becomes 80/16/4 with example 3.Use with example 3 in the same positive electrode of composition.When adjusting in the positive and negative electrode active material weight according to capacitance, mold pressing goes out Coin-shape cell shown in Figure 1.In the battery that obtains, positive electrode weight is 210mg, and negative electricity is 105mg very.

Because this battery negative electrode bulk density is 1.5g/cm ³, and low as the battery of example 22, so the active matter quality in this Coin-shape cell is less than example 3.

Example 24:

Use the chemical substance the same with example 1.At first, claim the sodium peroxide of 8.0g and the cobalt/cobalt oxide of 24.7g, in a mortar, fully will grind, mixture is stirred a few minutes with a high speed agitator, with a moulding press that partially mixed thing mold pressing is in blocks, sheet is done grinding again, and mold pressing is in blocks.This sheet ground again and mold pressing in blocks, this sheet of oven dry in electric furnace, elevated temperature progressively in empty sheet.Calcining is 10 hours in 550 ℃ of temperature.Natural cooling should be calcined goods, obtained sodium-cobalt alloy.When analyzing these goods, be confirmed to be β type sodium-cobalt/cobalt oxide with X-ray diffractometer.Check Na/C when using the ICP radioactive method.During atom ratio, found that it is 0.669/1.00.

This synthetic products is fully ground, obtain the powder of diameter less than 100mesh.With the method identical with example 3, the carbon black of 0.400 gram and EPDM mixture are sneaked into the 9.600 sodium-cobalt/cobalt oxide powders that restrain, claim 230mg this mixture, be the sheet of diameter 15mm with its mold pressing and a stainless steel expanded metal current-collector is included in wherein with the sheet moulding press, make not comprise expanded metal and equal 2.9g/cm in interior electrode bulk density ³It is anodal to use the electrode of so manufacturing to do, and makes negative electrode and electrolyte in the use-case 3 be assembled into a Coin-shape cell together.Firm ready-made cell voltage is 2.62V.

Method in the use-case 3 is done battery performance test.

Maximum discharge capacity is 17.1mAh, and it is the same with the battery that obtains in the example 3.But discharge capacity drops to 1/2 cycle lie weak point, equals for 143 cycles.One month self-discharge of battery rate is 3.5% in 25 ℃.

Example 25:

The method of use-case 1 is used the synthetic sodium-cobalt/cobalt oxide of same chemical substance, and it is done abundant grinding to obtain the powder of diameter less than 100mesh.

Polytetrafluoroethylene is added to the carbon black that is twice in the polytetrafluoroethylene amount in the polytetrafluoroethylene of swollen by the dimethylbenzene swollen, does abundant mixing again.Do dried and get rid of dimethylbenzene, remaining mixture fully mixes with above-mentioned sodium-cobalt/cobalt oxide, and making sodium-cobalt/cobalt oxide weight is 92%, and mixture weight is 8%.

This mixture is placed on the stainless steel metal sheet, and making and singly putting amount of area is 68.8mg/cm ²,, obtain the electrode of the long 268mm of wide 40mm with a pressure roller mold pressing.Turn up this electrode, make the stainless steel metal sheet, draw half length, active material is placed the both sides of electrode current-collector pasting.

The negative electrode of the composition identical with example 3 is placed on the nickel sheet metal, and the unit are amount is 31.5mg/cm ²,, form the electrode of a long 302.5mm of wide 40mm with a pressure roller mold pressing.

Turn up this electrode, make the nickel sheet to pasting, obtain half length, active material places the both sides of electrode gatherer.

In each electrode centers, draw a current collection end from collector plate, two surfaces of negative electrode are surrounded by two perforated membranes.Negative electrode is contained on the positive electrode and by rolling-in, makes negative electrode be positioned at the positive electrode outside, thereby form cylindrical electrode.This cylindrical electrode is placed in the cylinder of an AA size (external diameter 14mm, high 50mm).Used electrolyte is that concentration is the NaPF of 1mole/l in the mixed solvent (comprise 1,2-dimethoxy-ethane and the three water tetraethoxide diethyl ether that contracts, volume ratio is 1/6) ₆Solvent, this electrolyte is introduced into cylinder, and the negative electrode limit links to each other with cover, and this lid is buckled on the container and compresses with holding back the limit device, thereby adorns what a battery.

The cell voltage that has just installed is 2.52V.Discharge with the 100mA constant current value along the battery discharge direction.The discharge capacity that cell voltage is reduced to before the 1.7V is 330mAh.After static 30 minutes,, be raised to 3.2V until cell voltage with same current charges.Discharge after static 30 minutes and discharge and recharge retest.In the 5th cycle of test, discharge capacity is 554mAh, and maximum pd quantity is 572mAh, and 1/2 the cycle lie that capacitance is reduced to maximum discharge capacity was 209 cycles.

In this period measuring, in the 20-30 cycle, only discharge temp is changed to-20 ℃, and the inspection capacity.Minimum discharge capacity is 283mAh, and maximum discharge capacity is 289mAh.When low temperature, can keep enough characteristics even confirmed.

In the 25th cycle ,-20 ℃ of discharges down, discharging current is 20mA.Found to have obtained the discharge capacity of 428mAh.

Example 26:

Make same chemical substance used in the use-case 1.At first, claim 7.5 gram Na ₂O ₂With 30.8 gram Co ₃O ₄, with the synthetic sodium-cobalt/cobalt oxide of the method for example 1.According to analysis result, confirm that the Na/Co atom ratio is 0.5/l, unreacted Co ₃O ₄Stay among the γ type sodium-cobalt/cobalt oxide of formation.Method in the use-case 1 is used this synthetic electrode of goods mold pressing.

Utilize used negative electrode and electrolyte in positive pole for preparing like this and the example 1, with Coin-shape cell of the assembling of the method in the example 1.The cell voltage that has just installed is 2.58V.Do performance test with quadrat method in the use-case 1.Maximum discharge capacity is 12.5mA, and cycle lie was 123 cycles.Carry out the self discharge test in the 25th cycle.A purpose self-discharge rate is 3.7% in the time of 25 ℃.

Example 27:

Sodium-cobalt/cobalt oxide of manufacturing with the method identical with example 1 mode mixes with carbon black and EPDM in the mode of example 3, and making the mixed weight ratio of sodium-cobalt/cobalt oxide/carbon black/EPDM is 84/12/4.Mold pressing goes out the electrode of heavy 150mg diameter 15mm, makes that not contain current-collector be 1.6g/cm in interior electrode bulk density ³The electrode of so making is as positive electrode.Manufacture identical negative electrode in bulk density and composition and the example 3 with the same quadrat method of example 1, but weight change is 96mg.Make the electrolyte of using in the use-case 3.Use these positive electrodes, negative electrode and Coin-shape cell of electrolyte assembling.

Method in the use-case 3 is checked electrode performance.Maximum discharge capacity is 9.6mAh, and it was 124 cycles that discharge capacity drops to 1/2 o'clock cycle lie.A purpose self-discharge rate is 3.9% in the time of 25 ℃.

Example 28

A negative electrode is except being adjusted to 74/20/6 with Na2.7Pb/ carbon black/EPDM mixed weight ratio, and bulk density is 1.3g/cm ³And weight becomes outside the 90mg, and other all prepares with quadrat method by example 3 is described.A positive electrode is except weight is 178mg, and other all prepares with quadrat method by example 3 is described.Coin-shape cell is by using the same electrolyte that uses in the positive and negative electrode that so prepares and the example 3, by the assembling of the method described in the example 3.

The method of check battery performance is identical with example 3 described methods.Found that maximum discharge capacity is 10.3mAh, it is 112 times that discharge capacity reduces to 1/2 cycle life.Under 25 ℃ of conditions that continue 1 month, its self-discharge rate is 4.9%.

Comparative example 1

Use the negative electrode for preparing according to following method to replace employed negative electrode in the example 1.

Atomic ratio is that sodium, the lead alloy of 2.7/1.0 is placed in the drying box that is full of argon gas, wherein the content of water and oxygen is reduced to a few millionths (PPm), and this alloy by using a stainless steel mortar and stainless steel bar by pulverize fully.Its mean particle dia is less than 100mesh.Then, 200 milligrams of alloyed powders are 15mm and comprise in the disk of a nickel system porous metals gatherer at a diameter by pressing mold, and the thickness of electrode is regulated by example 1.The electrode that so prepares is promptly as negative electrode.

Same positive electrode and the electrolyte of Coin-shape cell by using the negative electrode that so prepares and using in example 1 assembles with quadrat method by example 1 is described.The voltage of the battery that has just assembled is 2.15 volts.

The method of check battery performance is identical with example 1 described method, its circulate at every turn and discharge capacity between relation shown in Fig. 3-(c).Maximum discharge capacity is 19.2mAh, and still, it only is 36 times that its capacity is reduced to 1/2 cycle life.Carry out the self discharge experiment at the 25th circulation time.In one month under 25 ℃ of conditions that continue 1 month self-discharge rate be 3.3%.

Comparative example 2

Use a negative electrode for preparing according to following method to replace the negative electrode that uses in the comparative example 1.Mix with EPDM in being dissolved in dimethylbenzene according to the comparative example 1 described sodium for preparing with quadrat method/lead alloy powder, thereby the weight ratio of alloy/EPDM is 99/1.As comparative example 1, by regulating its thickness disk that to form a diameter be 15mm.The electrode that so prepares is promptly as negative electrode.

By same positive electrode and the electrolyte that uses the negative electrode that so prepares and use in comparative example 1, Coin-shape cell presses that comparative example 1 is described to be assembled with quadrat method.The voltage of the battery that has just assembled is 2.50V.

This battery performance is according to testing with quadrat method with comparative example 1 is described.Relation between its each circulation and the discharge capacity is shown in Fig. 3-(d).Its maximum discharge capacity is 11.2mAh, and the cycle life that discharge capacity reduces to 9mAh is 70 times.The 25th circulation, self-discharge rate is tested.Found that self-discharge rate is 3.2%.

Example 29

Preparing of negative electrode

Taking-up is immersed in the interior high-purity sodium rod of Valelinum Liquidum and surfaces contaminated is scraped off.Sodium rod mixes (sodium/lead atom is than being 3.75/l) and its mixture in electric smelter with an amount of lead button, temperature is 500 ℃ and melted in lasting 3 hours.Then, temperature is reduced to 350 ℃ and annealing and is continued 20 hours.The temperature of alloy reverts to room temperature and this alloy is ground into powder in mortar.The carbon black of scheduled volume (Show-Black N110 is provided by Showa-Cabot) fully mixes with the alloy of pulverize.

The EPDM(JSR-EP57P that is dissolved in the scheduled volume in the cyclohexane is provided by Japan SYnthetic Rubber Co. Ltd) mix with said mixture and fully stirring.Above-mentioned predetermined quantity should make that the weight ratio of sodium alloy/carbon black/EPDM is 87/10/3.Said mixture is moulded to disk type negative electrode by tablet press machine, and its diameter is that 15mm and thickness are 300 μ m.Aforesaid operations all carries out in argon gas atmosphere.

The battery check

The negative electrode that the assembling utilization of Coin-shaped battery shown in Figure 1 prepares in a manner described, one by sneaking into through heating 10 parts of carbon blacks and 5 parts of polytetrafluoroethylene by Na ₂O ₂And Co ₃O ₄The Na that makes _0.67CoO ₂In, and mixture is pressed into disk and the positive electrode made, and 1,1 mol (mole/l) NaPF in the 2-dimethoxy-ethane ₆Solution as electrolyte, the check of battery is undertaken by following method.

On course of discharge, discharge, reduce to 1.7 volts (V) until cell voltage with 3 milliamperes of (mA) constant currents.Pause after 30 minutes, charge with 3 milliamperes of (mA) electric currents again, rise to 3.3 volts (V) until cell voltage.Pause after 30 minutes, discharge once more.Thereby carry out the charge-discharge duplicate test.

Maximum pd quantity is 12.2mAh, and discharge capacity to reduce to 1/2 cycle life be 320 times.At the 100th circulation and 200 circulation times, it is respectively 12.7% and 12.9% at 25 ℃ of self-discharge rates that continue 30 days.

Example 30

Manufacturing of negative electrode

Highly purified sodium piece and lead button are pressed sodium/lead atom than being the mixed of 3.75/l, and this mixture continues to melt in 4 hours under 500 ℃ of temperature, anneal under 350 ℃ of temperature, continue 15 hours and are cooled to room temperature.Formed alloy in mortar by pulverize fully, and the carbon black of scheduled volume (Black Pearl 2000 are provided by Showa-Cabot) sneak into the alloy of pulverize.Then, the EPDM(SSR-EP57P that is dissolved in the scheduled volume in the dimethylbenzene is provided by Japan SYnthetic Rubber Co. Ltd) in said mixture, stir.Predetermined quantity should make that the weight ratio of sodium alloy/carbon black/EPDM is 85/12/3.

Unnecessary dimethylbenzene under low pressure removes from said mixture, and the nickel screen that mesh size is 75mesh is placed on the mixture as reinforcing material, and this mixture is by the rolling method thin slice that to be pressed into a whole thickness be 380 μ m.Moulded body is cut into the check that suitable shape and cutting blade are used for battery performance.Aforesaid operations carries out in argon gas atmosphere.

The battery check

The assembling Coin-shaped battery must use the disk of an about 15mm of diameter, and it is to downcut on the negative electrode for preparing from above, and one by sneaking into through heating 5 parts of carbon blacks and 5 parts of polytetrafluoroethylene by Na ₂O ₂And Co ₃O ₄The Na that makes _0.87CoO ₂In and its mixture is pressed into a disk and the positive electrode made, and 1, the 1mole/lNaPF in the 2-dimethoxy-ethane ₆Solution as electrolyte.

The method of inspecting electrode performance is identical with method described in the embodiment 29.Maximum pd quantity is 12.4mAh, and it is 482 times that discharge capacity is reduced to the following cycle life of 10mAh, and at the 100th circulation and the 200th circulation time, it is respectively 12.2% and 12.5% at 25 ℃ of self-discharge rates that continue 30 days.

Example 31

Same negative electrode that each is prepared by embodiment 30 and positive electrode all place one as the nickel screen of current-collector and be pressed into a thin slice.Manufacture a column type battery cell that is of a size of the AA-3 type and must use the positive and negative electrode thin slice that so prepares, the two layers of polypropylene non-woven fibre is as separator, and 1,1mole/l NaPF in the 2-dimethoxy-ethane ₆Solution, as electrolyte.

In this battery cell, discharge with the 100mA constant current, reduce to 1.7 volts until cell voltage.After pausing 1 hour, charge, rise to 3.3 volts until cell voltage with same electric current.Pause after 1 hour, discharge once more, reduce to 1.7 volts until cell voltage.Thereby charge-discharge duplicate test.Maximum pd quantity is 390mAh, and the cycle life that discharge capacity is reduced to 200mAh is 245 times.

Example 32

Taking-up is immersed in the high-purity sodium rod in the Valelinum Liquidum, scrapes off surfaces contaminated, and the lead button that sodium is excellent and an amount of mixes (sodium/lead atom ratio is 3.75/1).This mixture melted with 500 ℃ of temperature in electric smelter in lasting 3 hours.Then, temperature drops to 350 ℃ and anneals, and continues 20 hours.After alloy temperature dropped to room temperature, this alloy was ground into powder in a mortar.The graphous graphite powder (being provided by Showa-Denko) of scheduled volume is added in the alloy of pulverize, and fully mix.The EPDM USR-EP57P that is dissolved in the scheduled volume in the cyclohexane is provided by Japan SYnthetic Rubber Co. Ltd) mix with said mixture and fully stirring.Predetermined quantity should make that sodium alloy/graphite powder/EPDM weight ratio is 82/15/3.Disk type negative electrode, its diameter are 15mm, and thickness is 300 μ m, by tablet press machine by top mixture compression moulding.Aforementioned operation is carried out in argon gas.

Assembling Coin-shaped battery as shown in Figure 1 must use the negative electrode that so prepares, and one by sneaking into through heating 10 parts of carbon blacks and 5 parts of polytetrafluoroethylene by Na ₂O ₂And Co ₃O ₄The Na that makes _0.67CoO ₂In and its mixture is pressed into disk and the positive electrode made, and 1,1mole/lNaPF in the 2-dimethoxy-ethane ₆Solution, as electrolyte.The service check of battery carries out as follows.

Discharge with the 5mA constant current at course of discharge, reduce to 1.7 volts until cell voltage.Pause after 30 minutes, charge, rise to 3.3 volts until its voltage with the 5mA electric current.Pause after 30 minutes, discharge once more.Thereby charge-spark gap inspection, maximum discharge capacity is that 12.2mAh and cycle life are 320 times.The the 100th and 200 circulation, it is respectively 10.5% and 11.2% at 25 ℃ of self-discharge rates that reach 30 days.

Example 33

Highly purified sodium piece mixes with lead button, thereby sodium/lead atom ratio is 3.75/1, and this mixture is melted at 500 ℃ and continues 4 hours, continues 15 hours 350 ℃ of annealing, is cooled to room temperature then.Resulting alloy in a mortar by pulverize fully, the thermal decomposition type graphite powder of scheduled volume is sneaked into the alloy of pulverize, and the EPDM(JSR-EP57P that is dissolved in the scheduled volume in the dimethylbenzene is provided by Japan SYnthetic Rubber Co. Ltd) stir with mixture then.Predetermined quantity should make that sodium alloy/graphite powder/EPOM weight ratio is 85/12/3.

Unnecessary dimethylbenzene under low pressure removes from said mixture, and the nickel screen that mesh size is 75mesh places on the mixture as reinforcing material, and this mixture is by the rolling method thin slice that to be made into a whole thickness be 380 μ m.

From the following diameter of negative electrode thin slice cutting for preparing thus is the disk of 15mm, and Coin-shaped battery as shown in Figure 1 is by using disk as negative electrode; One by sneaking into the polytetrafluoroethylene of 5 parts of heavy carbon blacks and 5 parts of weights through heating by Na ₂O ₂And CO ₂O ₄The Na that makes _0.67CoO ₂In and its mixture is pressed into a disk and the positive electrode made; And 1, the NaPF of the 1mole/l in the 2-dimethoxy-ethane ₆Solution be assembled as electrolyte, the check battery performance.

The check use-case 32 described methods of battery are carried out, and wherein, maximum discharge capacity is 12.2mAh, the cycle life that discharge capacity is reduced to 10mAh is 482 times, the 100th time and the 200th circulation, under 25 ℃ of conditions that continue 30 days, self-discharge rate is respectively 10.3% and 11.0%.

Example 34

High-purity sodium piece is mixed with highly purified tin particles, is 3.75/l thereby make the atomic ratio of sodium/tin.This mixture is continued to melt in 4 hours under 500 ℃ of temperature,, continue to anneal in 15 hours, be cooled to room temperature more then at 340 ℃.

The alloy that so prepares is fully ground in mortar, the alloy of grinding the graphous graphite powder that is provided by Showa Denko company of scheduled volume is provided again, and the EPDM(JSR-EP25X that will be dissolved in the scheduled volume in the dimethylbenzene is provided by Japan SYnthetic Rubber Co. Ltd) stir with this mixture, predetermined amount should make that the weight ratio of sodium alloy/graphite powder/EPDM is 82/14/4.

It is 15mm that mixture is pressed into diameter by tablet press machine, and thickness is the sheet negative electrode of 300 μ m.

Coin shape rechargeable battery as shown in Figure 1 is by the positive electrode that adopts the negative electrode that so prepares and use in example 1 and 1, the NaPF of 1mole/l in the 2-dimethoxy-ethane ₆Be assembled as electrolyte.Rechargeable battery is tested.The method of inspection is identical with example 1, and wherein, maximum discharge capacity is 11.5mAh, and it is 273 times that discharge capacity reduces the following cycle life of 10mAh.The 100th time and the 200th circulation, under 25 ℃ of conditions that continue 30 days, self-discharge rate is respectively 9.8% and 12.8%.

Example 35

With Na ₂O ₂/ CO ₃O ₄Molal weight than for the 1.26(Na/Co atomic ratio be 0.84) with Na ₂O ₂And Co ₂O ₄Mix, mixture is molded into disk, under dried oxygen atmosphere, be raised to 740 ℃ with 4 ℃/minute speed temperature, calcined 24 hours down at 740 ℃ then, then, the product of calcining is naturally cooled to room temperature and is fully ground in mortar, the EPR(ethylene/propylene rubber of the carbon black of 10 parts of weight and 2.5 parts of weight then) mixing as the sodium-cobalt/cobalt oxide of adhesive with 100 parts of weight, then, is that the disk of 15mm is included in the disk nickel screen link thereby mixture is moulded to diameter.The electrode that so prepares is as positive electrode.

Negative electrode is by it is dissolved in dimethylbenzene as adhesive and sneaks into sodium/lead alloy (the Na/Pb atomic ratio is 2.7) 100 parts of weight, that fully grind under low pressure remove dimethylbenzene in mortar with the EPR fine powder (ethylene/propylene rubber) of the carbon black of 10 parts of weight and 2.5 parts of weights, and mixture is molded into diameter is the disk of 15mm so that the nickel screen current-collector is included in the disk.

The Coin shape rechargeable battery is by adopting the positive electrode that so prepares and negative electrode and 1, the NaPF of 1.5mole/l in the 2-dimethoxy ethene ₄Solution is assembled as electrolyte.In this battery, charge and discharge constant current with 5mA in voltage range is 1.7V～3.2V repeats.Discharge capacity, cycle life and self-discharge rate are after 60 ℃ of temperature reach 20 days, after the 100th charging, be verified, find that thus the maximum discharge rate in each circulation is 16.2mAh (corresponding to 0.42 electron equivalent of each CO atom (electric equivalent)), cycle life is 320 times, and self-discharge rate is 10.5%.

Example 36

With Na ₂O ₂/ CO ₃O ₄Molal weight be 1, with Na ₂O ₂With CO ₃O ₄Fully mix (the Na/CO atomic ratio is 0.67), and this mixture is molded into disk, use-case 1 described method is made the dish type positive electrode that diameter is 15mm by above-mentioned disk.

Negative electrode is by sneaking into 10 parts of heavy graphite powders and 2.5 heavy EPDM in the sodium/lead alloy of 100 parts of weights that fully grind through mortar, they fully mixed and by example 1 described method mold pressing.

Similar battery cell of battery for preparing with example 1 so prepares positive electrode and is assembled at embodiment 1 used negative electrode and electrolyte by adopting.The performance of battery cell is with the check of use-case 1 same procedure, and wherein, maximum discharge capacity is that 14.7mAh(is corresponding to each CO atom 0.38 electron equivalent), cycle life is 387 times, self-discharge rate is 10.3%.

Example 37

A positive electrode is except that becoming the Na/CO atomic ratio 0.6, and other all prepares by embodiment 35 described methods.A Coin-shaped battery is assembled with the identical negative electrode and the electrolyte that use in example 35 by the positive electrode that uses so to prepare.After calcining, positive electrode active substance must be through x-ray diffraction technique, and about 10% CO is found in initial analysis ₃O ₄Unreacted still in r-type sodium-cobalt/cobalt oxide.

The performance of battery is used with embodiment 1 is described and is checked with quadrat method.Maximum discharge capacity is 114.0mAh, and cycle life is 218 times, is 12.5% at 60 ℃ of self-discharge rates that continue 20 days

Example 38

A Coin shape rechargeable battery becomes 0.92 except that the Na/CO atomic ratio, and other all presses embodiment 35 described method assemblings, and the performance of check storage battery, and maximum discharge capacity is 14.3mAh, and cycle life is 153 times, and self-discharge rate is 13.5%.

Example 39

The high-purity sodium rod that is dipped in the paraffin oil is taken out and contaminated surface is scraped off; the lead button mixing (the Na/pb atomic ratio is 2.7/1) of sodium rod and appropriate amount and mixture are in electric smelter; temperature is 500 ℃ and reaches 3 hours and melt; then; temperature is reduced to 350 ℃; annealing reaches 20 hours, and the temperature of alloy is got back to room temperature and alloy is ground into powder in mortar.The people of scheduled volume is made graphite powder (Showa Denko company provides) and carbon black (Black Pearl

2000Showa-Cabot company provides) sneaked into and ground the back alloy, and fully mixed.

The EPOM(JSR-EP57P of the scheduled volume that will dissolve in cyclohexane is provided by Japan SYnthetic Rubber Co. Ltd) and said mixture mixes and stirring, obtaining to have sodium alloy gold/graphite powder/carbon black/EPDM weight ratio is 88/5/5/2 mixture.

With the mold pressing pelleter said mixture is molded into that to have diameter be 15mm, thickness is the disc negative electrode of 300 μ m, and aforementioned each operation is all carried out in argon gas atmosphere.

By adopting the negative electrode that so prepares, positive electrode and electrolyte are assembled by Coin shape rechargeable battery shown in Figure 1, and wherein positive electrode is the carbon black with 10 parts of weights, 5 parts of heavy polytetrafluoroethylene sneak into 100 parts of weights under heating with Na ₂O ₂And CO ₃O ₄The N for preparing _A0.67CoO ₂In and mixture is pressed into a disk prepares, electrolyte then is 1, the NaPF of 1mole/l in the 2-dimethoxy-ethane ₄Solution.

The rechargeable battery experiment is undertaken by the Coin-shaped battery that adopts assembling like this.Originally, at course of discharge, electric current discharges under constant current value 5mA and reduces to 1.7V until cell voltage.Pause after 30 minutes, charging until cell voltage with the constant current of 5mA is 3.2V.Pause after 30 minutes, discharge is carried out once more, tests repeatedly thereby carry out charge-discharge.

Maximum discharge capacity is that 15.0mAh and cycle life are 350 times, at the 100th time and the 200th circulation time, reaches under 30 days the condition at 250 ℃, and self-discharge rate is respectively 4.8% and 5.2%.

Example 40

High-purity sodium piece than under mixes with lead button at sodium/lead atom of 2.5/1, and this mixture continues down to melt in 4 hours at 500 ℃, then at 350 ℃ of annealing 115 hours down, cool to room temperature again.The alloy that obtains is fully ground in mortar, again with the thermal decomposition type graphite powder of scheduled volume by method of vapor-phase growing (providing) and carbon black (Black Pearl by Showa Denko company

2000 are provided by Showa-Cabot company) be added in the alloy of grinding, and the EPDM(JSR-EP57P of scheduled volume is provided by Japan SYnthetic Rubber Co. Ltd) to mix with said mixture and stir the weight ratio that forms sodium alloy/graphite powder/carbon ink/EPOM be 89/3/6/2 mixture.

Under low-pressure, unnecessary dimethylbenzene removes from said mixture, and the nickel screen with 75mesh is used as the reinforcing material of mixture, with rolling process mixture is pressed into the sheet that whole thickness is 380 μ m.

Cut the disk of the about 15mm of diameter down from the negative electrode that so prepares.Coin-shaped battery as shown in Figure 1 is by adopting dish type such as the electroplax that so prepares; Again 5 parts of heavy carbon blacks and 5 parts of heavy polytetrafluoroethylene are sneaked into 100 parts of weights, under heating condition by Na ₂O ₂And CO ₃O ₄The Na that forms ₀₆₇COO ₂In and mixture is molded into the positive electroplax that disk is made; And 1/ 1, the NaPF of 1mole/l in the 2-dimethoxy-ethane ₆Solution is assembled as electrolyte.

The performance of battery is by embodiment 39 described method checks, maximum pd quantity is 15.2mAh, and it is 395 times that discharge capacity reduces to the cycle-index that is lower than 10mAh, when the 100th time and 200 times, in temperature is that self-discharge rate is respectively 5.3% and 5.5% under 25 ℃ of conditions that continue 30 days.

Example 41

High-purity sodium piece is 2.7/1 to mix with high-purity tin grain with sodium/tin atom ratio, this mixture is continued to melt in 4 hours under 500 ℃ temperature, and be annealing 15 hours cool to room temperature then under 340 ℃ of conditions in temperature.

The alloy that is obtained is fully ground in a mortar, the carbon black of the graphite powder of the scheduled volume that will be provided by Showa Denko company and the scheduled volume that provided by Showa-Cabot company is sneaked in the alloy after the grinding, and the EPDM(JSR-EP25X of the scheduled volume that will dissolve in dimethylbenzene is provided by Japan SYnthetic Rubber Co. Ltd) to mix with said mixture and stir, the weight ratio that obtains a kind of sodium alloy/graphite powder/carbon black/EPDM is 83/5/8/4 mixture.

It is 15mm that this mixture is compression molded into diameter by a kind of tablet press machine, and thickness is the disc negative electricity plate of 300 μ m.

Coin-shaped battery as shown in Figure 1 is by adopting the negative electricity plate that so prepares, as positive electroplax used among the embodiment 39 and 1, and the NaPF of 1 mol in the 2-dimethoxy-ethane ₆Solution is assembled as electrolyte.Use-case 39 is described tests to the battery of assembling like this with quadrat method, wherein, maximum pd quantity is 12.5mAh, it is 595 times that discharge capacity reduces to the cycle-index that is lower than 10mAh, at the 100th time and the 200th time, in temperature is that self-discharge rate is respectively 4.8% and 4.7% under 25 ℃ of conditions that continue 30 days.

Example 42

A negative electrode is except the mixture with 10.2g, and this mixture comprises that weight ratio is 3/1 carbon black (Black Pearl 2000 are provided by Showa-Cabot company) and acetylene black (Denka Black

Provide by Denki kagaku kogyo) replace carbon black (Black Pearl used in example 1 2000 are provided by Showa-Cabot company), this mixture is mixed with 2.5gEDPM, again 10g gained mixture is mixed with the 67.0g alloyed powder, and beyond the mixture mold pressing with the 130g gained, other all prepares with embodiment 1 same procedure.

Coin-shaped battery is by the negative electrode that adopts so to prepare and the positive electrode identical with example 1, and electrolyte and current-collector are assembled.The cell voltage that has just assembled is 2.51v.Discharge at the constant current of course of discharge with 2.5mA, before cell voltage was reduced to 1.70V, the electric weight that can put was 10.4mAh.The performance test of battery can be undertaken by the method for example 1.In the 5th circulation time battery discharge capacity is 17.8mAh, and the maximum discharge capacity of being put down in writing is that 18.5mAh occurs in the 14th circulation, and it is 325 times that capacity is reduced to 1/2 cycle life, and under 25 ℃ of conditions that continue 1 month, self-discharge rate is 3.3%.

Example 43

A negative electrode is except using acetylene black (Denka Black

Provide by Denki kagaku kogyo) replace used carbon black (Black Pearl among the embodiment 1 2000 are provided by Showa-Cabot), the weight and the bulk density of removing the outer negative electrode of current-collector become 150mg and 2.4g/cm ³Outward, other all prepares by example 1 described method.

A Coin-shaped battery is by negative electrode that adopts so to prepare and the identical positive electrode that uses in example 1, separator and electrolyte are assembled, battery performance to assembling like this is tested, maximum discharge capacity the 12nd record is 18.3mAh, it is 352 that capacity is reduced to 1/2 cycle-index, is 3.2% at 25 ℃ of self-discharge rates that continue 1 month.

Example 44

Experiment except with three water diethyl acetal dimethyl ether as the solvent of electrolyte replace example 3 used 1, outside the 2-dimethoxy-ethane, other is all undertaken by example 3 described methods.

The maximum discharge capacity of the rechargeable battery that obtains is 14.5mAh, and cycle life is 406 times, and self-discharge rate is 3.2%, and under-20 ℃ condition, discharge capacity is 7.0mAh.

Example 45

Experiment except adopt 1-ethyoxyl-2-Ethyl Methyl Ether as electrolyte replace in example 3, adopting 1, outside the 2-dimethoxy-ethane, other is all undertaken by example 3 described methods.

The maximum discharge capacity of the rechargeable battery that is obtained is 14.3mAh, and cycle life is 398 times, and self-discharge rate is 3.1%, and under-20 ℃ temperature, discharge capacity is 7.1mAh.

Example 46

Experiment replaces the used carbon black (Showa-Black of embodiment 3 except adopting a kind of mixture as material with carbon element Outside N110 was provided by Showa-Cabot, the graphite fibre (being provided by Showa-Cabot) and carbon black (the Black Pearl that are prepared by vapor growth method of 1/1 weight ratio was provided this mixture 2000 are provided by Showa-Cabot), other is all undertaken by example 3 described methods.

The maximum discharge capacity of institute's acquisition rechargeable battery is 16.8mAh, and cycle life is 425 times, and under 25 ℃ of temperature, the self-discharge rate that continues 1 month is 3.4%.

Can be found out that by foregoing content rechargeable battery of the present invention has high-energy-density, long circulation life, the performances such as high speed charge and discharge are possible. In addition, rechargeable battery of the present invention has good low-temperature characteristics and high-performance. Moreover this battery can have various shapes. For example: button cell, Coin-shaped battery and cylindrical battery.

Claims (18)

1, a rechargeable battery comprises a positive electrode, a negative electrode and a kind of non-aqueous eletrolyte, wherein positive electrode comprises that a kind of sodium-cobalt/cobalt oxide is as Main Ingredients and Appearance, negative electrode is by containing sodium alloy, the synthetic of material with carbon element and adhesive is formed, and non-aqueous eletrolyte is made up of sodium salt and ether compound.

2, rechargeable battery according to claim 1, wherein, the main component of electrode is sodium and at least a metal of selecting from plumbous and tin.

3, rechargeable battery according to claim 1 and 2, wherein, carbon is selected from carbon black and graphite as the part of negative electrode.

4, according to claim 1,2 or 3 described rechargeable batteries, wherein, adhesive is an olefin copolymer type rubber as the part of negative electrode.

5, according to claim 1,2,3 or 4 described rechargeable batteries, wherein, negative electrode comprises the sodium alloy of at least 80% weight, the adhesive of the carbon of 3-20% weight and 1-8% weight.

6,, wherein, be 0.65/1-0.90/1 as the scope of sodium/cobalt atom ratio in the sodium-cobalt/cobalt oxide of the Main Ingredients and Appearance of negative electrode according to the described rechargeable battery of claim 1-5.

7,, wherein, comprise at least 70% γ type crystal structure as the sodium-cobalt/cobalt oxide of the part of positive electrode according to any described rechargeable battery among the claim 1-6.

8, according to any described rechargeable battery among the claim 1-7, wherein, positive electrode is by containing sodium-cobalt/cobalt oxide, and the mixture of carbon black and adhesive is formed, and wherein the weight of carbon black is no more than 7%, and the weight that contains adhesive is no more than 6%.

9,, wherein, be fluorohydrocarbon (fluorohydrocarbon) resin or olefin copolymer type rubber as the adhesive of positive electrode part according to any described rechargeable battery among the claim 1-8.

10,, wherein, be NaPF as the sodium salt of the part of non-aqueous eletrolyte according to any described rechargeable battery among the claim 1-9 ₆Or NaBF ₄

11, according to any described rechargeable battery among the claim 1-10, wherein at least a of ether compound as the non-aqueous eletrolyte part is the compound that is selected from following general formula representative, and general formula is:

R wherein ¹And R ²Independent representative has the alkyl of 1-8 carbon atom, and m is 2 or 3, and n is an integer among the 1-8.

12, according to any described rechargeable battery among the claim 1-10, wherein, be 1 as the ether compound of non-aqueous eletrolyte part, the 2-dimethoxy-ethane.

13, according to any described rechargeable battery among the claim 1-10, wherein, as the ether compound of non-aqueous eletrolyte part is from three water, the three dimethylamino ethanol ethers that contract, three water, the three ethanol diethyl ether that contract, the three water tetraglyme that contracts, the three water tetraethoxide diethyl ether that contracts, the three water dipropyl diethylene glycol dimethyl ether that contracts, three water, the three propyl alcohol dimethyl ether that contract are selected in three water diethyl acetal dimethyl ether and the 1-ethyoxyl-2-Ethyl Methyl Ether.

14, according to any described rechargeable battery among the claim 1-10, wherein the ether compound as non-aqueous eletrolyte is a kind of mixture, and this mixture comprises 1,2-dimethyl ethane and by a kind of compound of following general formula:

R wherein ¹And R ²Represent an alkyl with 1-8 carbon atom separately, m is 2 or 3, and n is an integer among the 1-8.Its mixed volume of said mixture is than being 20/1-1/2.

15, according to any described rechargeable battery among the claim 1-10, wherein, be 1 as the ether compound of non-aqueous eletrolyte, the contract mixture of tetraethoxide methyl ether of 2-dimethoxy-ethane and three water, its mixed volume is than being 20/1-1/2.

16, according to any described rechargeable battery among the claim 1-15, wherein, the bulk density of removing the outer positive electrode of current-collector is 2.3-3.5g/Cm ³, and negative electrode is 1.7-2.5g/cm ³

17, a kind of method that forms anhydrous charging battery electrode, it comprises by using adhesive to form a positive electrode or negative electrode, wherein adhesive expands or is dissolved in the organic solution, expand or the adhesive of dissolving mixes mutually with carbon, mixture directly mixes with sodium alloy or sodium-cobalt/cobalt oxide or removes mixing again behind the organic solvent then.

18, method according to claim 17, wherein organic solvent is dimethylbenzene or cyclohexane.

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