JPH05501937A - Solid metal-sulfur cell - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The invention described herein is the subject of a contract between the U.S. Department of Energy and the University of California. DE-AC03-763FOOO98, and the U.S. government have the right to the invention.

The present invention relates to a metal-sulfur type cell for manufacturing a secondary battery, particularly in a solid state. relates to a cell that operates with its constituent parts.

Secondary batteries are widely used in modern society, especially in applications that do not require large amounts of energy. used in However, storage batteries cannot be used in applications that require significant amounts of power. Developing storage batteries that are desirable and suitable for high power applications such as electric vehicles. A great deal of effort is expended to Of course, such storage batteries can also be used for cameras or is suitable for use in low power applications such as desktop recording devices.

At present, the most common secondary battery is probably the lead-acid battery used in automobiles. be. Batteries can be operated for many charge cycles with little loss of performance. It has the following advantages. However, such storage batteries have a low power-to-weight ratio. Ru. In order to improve the weight ratio, lithium storage batteries have been well studied and the It is promising for various applications. Since it has been improved, it can be used even more widely. It is recognized that the technology will be developed later.

The development of lithium polyethylene oxide cells typically has a coefficient of performance (F OM), and this factor is calculated by multiplying the number of cycles by the average cycle capacity. , and is calculated by dividing by the excess set lithium capacity. This way A representative example of the cell is found in US Patent No. IE 4.589.197, and this lithium/polyethylene battery systems with electroactive materials or intercalation compounds. It is listed. Additionally, this type of battery can be scaled up to large sizes with little loss in performance. It has been shown that it can be scaled up.

Other lithium-type cells are found in U.S. Pat. No. 4,833,048, which This is a sulfur-sulfur bond in the charged state (these bonds are broken down in the discharged state to form organometallic using an organic sulfur anode (which produces salts). This patent has an excellent weight ratio. However, the disclosed electrodes are used in liquid form and the desired voltage is A solvent was required to provide flow transport. The present invention is a modification of the series of these patents. It adds goodness. Specifically, the present invention provides the ability to operate at room or ambient temperature. It provides a cell with a FOM of the order of 120 along with a force.

Summary of the invention Therefore, the main object of the present invention is to have a high coefficient of performance and yet be able to operate at ambient temperature. An object of the present invention is to provide a metal-sulfur type cell.

Another object of the invention is that all components are in solid state and yet have reproducible performance. It is an object of the present invention to provide a cell that can be reliably processed into a unit that has a value.

Yet another object of the invention is the need for load leveling and/or automotive applications. The object of the present invention is to provide a storage battery having an energy-to-weight ratio far exceeding .

These and other objectives will become apparent as the specification progresses.

According to the present invention, a composite anode and a storage battery system made of a composite anode system are provided.

In a fully charged state, the anode is a one-, two-, or three-dimensional polymeric electroactive component. including. In one-dimensional linear form, this component is (SRS), where R is and n is greater than 2 in the charged state, preferably or greater than 20). The half-cell reaction is expressed as below. It can be said that (SRS), +2n e-=n-SRS- and all cells are reversed. The response can be expressed as follows.

(SRS) s+2nLi=nLizSRS In the most general sense, solid state existence The electroactive component of the sulfur electrode can be represented by (R3, ) in the charged state. . where y is 2 to 6, n is greater than 2, preferably greater than 20, and R is one or more different aliphatic or aromatic moieties having 1 to 20 carbon atoms moieties, and these moieties include one or more aromatic rings when R contains one or more aromatic rings. or R contains an aliphatic chain, one or more oxygen, phosphorus, silicon, It may contain sulfur, nitrogen or fluorine atoms, and the aliphatic group may be linear; or may be branched, saturated or unsaturated (, aliphatic chains or The aromatic ring may carry a substituent, and the organic sulfur anode described above is in a charged state. The cell is further characterized by a large number of sulfur-sulfur bonds, and these bonds are responsible for the discharge of the cell. It is later decomposed to produce metal ions and organometallic salts in the cell.

The charge/discharge process in the anode is a reversible redox polymerization (or monomer R55R In the case of compounds, it can be considered as redox dimerization/cleavage). 2D (Ladder polymer)! An example of a pole is polyethyleneimine disulfide such as It can be shown by

These polymeric electrode materials transport alkali metal ions, but often internally Polymers suitable for rapid ion transport within the electrode, as is done in doped electrodes. – Necessary or desirable to contain an electrolyte, e.g. polyethylene oxide be done. Furthermore, since organosulfur electrodes are not conductive, a small amount of carbon black ( conductor particles (typically 7% by weight) or equivalent are dispersed in the composite electrode. This is very important. The range of these materials in the polymer anode is about 30% by weight to 8% 0% by weight active organic sulfur, about 20% to about 70% by weight polymer electrolyte, and From about 1% to about 20% by weight conductor particles.

The desired mixture is in acetonitrile (SR3). Polymer, polyethylene oxide side, and dissolve or disperse the carbon black powder, followed by evaporation of the solvent. casting a thin film (e.g. 10-200 microns) solid composite electrode. It is obtained by In preferred cases, the anode is made of an organic sulfur redox polymer, polyester. This is a composite electrode containing tyrene oxide and carbon black.

In a fully charged state, the organic sulfur anode has the general formula (SR3), later, Its important feature is the formation of sulfur-sulfur bonds after oxidation of the alkali metal thiosalt.

Preferred electrodes are polymeric disulfides, but US Pat. No. 4.833.048 Monomeric disulfide (RSSR) as described in It is considered to be effective for storage batteries in the state. In a fully discharged state, the organic sulfur battery The electrodes are polythioanions and/or dispersed in a polymer electrolyte matrix. Contains dithioanion (-SRS-). The final discharge product is, of course, a polymer chain It depends on the type of R groups therein and the number of dimensions of the fully oxidized polymer anode.

Another advantage of the present invention lies in the ability of solid state electrodes to be reversible to a variety of metals. be. Although lithium has the advantage of lowest equivalent weight and equivalent weight, it It is more expensive than Umu. In addition, preferred polyesters such as polyethylene oxide The conductivity of the electrolyte is higher for sodium transport than for lithium transport. stomach. Therefore, as a practical matter, intercalation cells require lithium, or this electrode The negative electrode may include many different metals. Therefore, alkali metals or Potassic earth metals or transition metals (polyether electrolytes contain divalent metals such as Zn″+) ), especially containing lithium and/or sodium Mixtures are also within the scope of this invention.

The electrolyte used in the cell of the present invention can be used as an electrode separator and as a metal ion Acts as a transport medium for water. Therefore, any solid material capable of transporting metal ions fees may be used. For example, sodium beta alumina has been shown to be effective.

However, solid electrolyte separators do not contain suitable electrolyte salts or suitable electrolyte salts. Polymer electrolytes such as polyethers, polyimides, polythioethers, polyphos Preferably, they are sphazenes, polymer blends, etc.

Brief description of the drawing FIG. 1 is a cross-sectional view of the main components of a cell made according to the present invention.

FIG. 2 illustrates the operation of one embodiment of the present invention and compares it with data of a prior art embodiment. The data to be compared is shown in graphical form.

Detailed description of the invention A metal-sulfur content cell such as that shown in FIG. A current collector I3 in parallel with the pole I4, and an electrolyte sandwiched between the negative pole I2 and the positive pole I4. Contains 15.

A typical cell may contain all of these components or a suitable case such as plastic (see fig. (not shown) with only the current collector extending beyond the enclosure.

In this way, reactive metals such as sodium or lithium in the anode are protected. It will be done. Similarly, protection of other parts of the cell is provided.

Suitable battery structures include cell components and known methods for assembling the cell, if desired. any of the known forms can be made by the technique and using the present invention. Can be processed. The exact structure mainly depends on the intended use for the storage battery unit. Depends on. However, all cell units are substantially solid during operation at ambient temperature. It is recognized that this is a physical condition.

Referring again to FIG. 1, current collectors 11 and 13 are made of a conductive material such as stainless steel. sheets, which remain substantially unchanged during cell discharging and charging. , and provide current connections to the cell's cathode and anode. The negative electrode 12 is made of lithium or or an alkali metal such as sodium, preferably sodium or lithium. It is preferable to The organosulfur cathode or anode I4 is a foil on top of the current collector I3 described above. and the entire unit is pumped with electrolyte I5 sandwiched between the electrodes as shown. will be responded to.

In the drawing, the thickness of all cell components are exaggerated for illustrative purposes; All of the components are typically fairly thin sheets. For example, a typical Lichiu The aluminum or sodium solid anode 12 is approximately 10 to 50 microns thick and typically The typical solid composite polymer cathode 14 is approximately 50-100 microns thick. , a typical PEO electrolyte 15 is approximately 10-100 microns thick.

A preferred electrolyte is LiN(CF3SO,)! Plasticizing electrolyte salts such as Polyalkylene oxide such as polyethylene oxide. plasticizing electrolysis The effect of the salt is to maintain the polyether in an amorphous (conductive) state at low temperatures; This allows the cell to operate at low temperatures.

According to the present invention, the organic sulfur compound constituting the novel anode of the present invention has an organic moiety and an organic moiety. One sulfur atom forms a bond with another sulfur atom when the organic sulfur material is in its charged state. (which is also bonded to the organic moiety) and at least one sulfur bond forming a second bond. Characterized by organic sulfur materials with yellow atoms. The compound is in its discharge state When the sulfur-sulfur bond is broken down, metal ions such as sodium or Each of the organic sulfur anions produced forms a salt.

Thus, the anode material comprises an organic sulfur material having the basic formula or backbone formula R-3-. .

In its charged state, one or more sulfur atoms (described below) form a -5-3- bond. and the sulfur atom of another R-8- group forms R-3-5-R. After discharge, 5 The -8- bond is broken and the respective S- group is separated from the metal ion, e.g. sodium. A salt such as R-3-Na is produced.

Additionally, the R group representing an organic moiety may be attached to it by a double bond, as explained below. Not only can there be a bonded sulfur atom, i.e. R=S, but also the above sulfur Can have atoms. Furthermore, in the case of, for example, -5-R-S-, the R group is a single has more than one sulfur atom attached to it by a bond, thus allowing polymerization Make it.

Also, when the R group has three or more such sulfur atoms single-bonded to it, may branch or grow.

Therefore, the general formula of the organic sulfur material constituting the novel anode of the present invention is that its state of charge is So, it can be written as (R(S)a)6. In the formula, y is 2 to 6, and n is 20 R is one or more homologous or heterogeneous lipids having from 1 to 20 carbon atoms. aliphatic organic moieties or aromatic organic moieties, where R is one or more aromatic organic moieties. If it contains an aromatic ring, it contains one or more oxygen, sulfur, phosphorus, silicon or nitrogen heterocycles. atoms or, if R includes an aliphatic chain, 1 associated with that chain. may contain more than one oxygen, phosphorus, silicon, sulfur, nitrogen or fluorine atom; Aliphatic groups may be linear or branched, saturated or unsaturated. The aliphatic chain or aromatic ring may have a substituent.

If n in the general formula (R(S)a) is greater than 2, the amount of organic sulfur anode material an organic moiety containing more than one sulfur atom, at least in part bound to the same organic moiety and can form sulfur-sulfur bonds with sulfur bonded to another organic moiety. child Thus, in its charged state, the polymeric material is free from impurities or to stop polymerization. monosulfide organic moieties, e.g., chain termination such as CH=-CH2-5-Na Polymer lengths can be produced depending on the presence of the agent. For example, such polymers , a linear aliphatic chain bearing such a sulfur atom at each end of the chain, e.g. 3-CH, CH2-5-, dimers, oligomers, etc., e.g. -3-CH2CH, -3-S-C)1 corresponding to the general formula (R(S)!), ．． cH, -3-S-CH, CI (enables the production of 2-3-).

Similarly, organosulfur compounds have sulfur-sulfur bonds with adjacent sulfur atoms of other organosulfur materials. branched polysulfide materials containing more than two sulfurs capable of forming . For example, if each R group contains three sulfur atoms capable of forming a sulfur-sulfur bond , the general formula can be written as (R(S), ).

Thus, y depends on the presence of a doubly bonded sulfur atom in the R group as well as the similar The possibility of the presence of more than one sulfur atom that can form a sulfur-sulfur bond with the sulfur atom of A value of 1 to 6 was given in the general formula in recognition of both abilities. The value of n in the general formula is 2 Greater than 0 or preferred, possibility of low steps of polymerization, e.g. by ring formation It also has advantages in solid-state storage batteries and non-polymerizing organic sulfur compounds. Therefore, a range including 2-20 was given. No upper limit was imposed on n.

After all, the degree of polymerization depends on the nature of the organosulfur compound used and under the charging conditions. This is because it is restricted.

The oxidation-reduction chemistry of organosulfur electrodes is fully described in U.S. Pat. No. 4,833,048. , and relevant parts thereof are included for reference. The present invention They differ by using similar organic sulfur electrodes or by operating at low temperatures in the solid state.

Therefore, the present invention provides that the monomer units have a monomer unit of more than 20, preferably more than 50, Machines prefer sulfur polymers. In addition, the anode of the present invention uses special current transport additives. This makes it different from the anode in the cited patent.

The operating temperature of solid-state cells ranges from -40°C to 145°C, and the electrode or electrolytic Limited to a high range by the melting point of the quality. The preferred temperature range is from ambient temperature to 100°C. up to ℃. Although sodium negative electrodes are limited to temperatures below 98 °C, Na4P Sodium alloy electrodes such as those in solid form above 100"C can be used successfully. .

The use of solid polymer electrolytes and solid redox polymerization cathodes can be It allows production in an all-solid state without the difficulties associated with the use of electrolytes.

The adhesion and elasticity of solid polymer electrolytes and solid redox polymer cathodes are prevent loss or significant degradation of electrical contact between the solid electrolyte and the electrodes during the cycle. Canada Additionally, the present invention provides for the replacement of certain types of liquid corrosive materials by solid, safe compositions. Provide improvements to the state of the art. This substitution makes storage batteries using the present invention highly automated methods make it much easier to manufacture and package containers. Provides cells that are non-corrosive to the material.

The following examples of laboratory tests serve to further illustrate the invention.

Sodium negative electrode, sodium β-alumina electrolyte, and (SRS)n, polyethylene A laboratory battery was assembled with an anode made of ren oxide and carbon particles. . The (SR3)n polymer used was 2.5 dimercapto, 3. 4thiodiazo The three units of the polymer are represented by the following structural formula.

The composite anode has a thickness of approximately 100 microns, which is approximately 0.0115 g/cm" electrode surface. (which can be translated as area). 100 micron polymer film The effective capacity is approximately 6.4 coulombs/cm2 or 1.8 mAh/cm". Ta. Bring the assembled cell to the endpoint of 6 coulombs (defined as 100% capacity) ) was cycled. These cells were subjected to various temperatures and conditions for a total of 80 cycles. The battery was charged and discharged at high current densities, with no apparent evidence of performance deterioration. 13 At an operating temperature of 0°C, the cell was charged to 100% effective key at a current density of 41 TIA/Cm2. It can be discharged to capacity and fully recharged at a current density of 3mA/cm2, and There were no negative effects on subsequent cycles. Furthermore, the cell has a high ratio of around 10mA/cm2. It can discharge up to 50% effective capacity at a rate as high as 6mA/cm2. It was able to charge at 65% effective capacity. Furthermore, these exceptionally high charging/discharging The flow density did not harm the integrity of the solid polymer electrode. The results of these studies are Demonstrates reversibility and reliability of solid redox polarized electrodes even under novel electrochemical conditions did.

Lithium negative electrode, polyethylene oxide electrolyte, and (SR3)n polymer, A cell made with an anode made of polyethylene oxide and carbon particles. , was created to test the actual performance of thin film storage batteries made in accordance with the present invention. . The solid electrolyte used in these cells was lithium triflate (LiCF, 5 O-), lithium barchlorate (LiCIO4), or other suitable electrolyte It was polyethylene oxide doped with salt. The concentration of electrolyte salt is salt There are 8 PEO monomer units (CH2CH,O) per molecule, and herein P It is abbreviated as E0sL+X, where X is the salt anion. organic used The sulfur polymer was the same as the polymer described above for the sodium cell.

Two thicknesses of electrodes for high power density storage batteries: high capacity 6 quartz/ cm2 film (100 microns) and low capacity 3K/cm2 Regarding sodium-based cells, except for casting a film (50 microns) of The composite anode was assembled as described above. These Li/PEO/[(SR3 ) n/PEO/C] cell has a theoretical energy density of 1000 Th/kg, and The assembled cell consists of the actual electrodes, PEO film, and excess lithium of 41 The electrode had a large excess of lithium). Actual energy of 338 Th/kg (zero current train) for the film of 304 Wh/kg for low capacity films with It had energy density. These cells were charged for a total of 350 cycles. The battery was discharged at two different discharge levels. The first 100 cycles are Discharge to 80% depth, remaining 250 cycles to 50% capacity depth It was discharged until The demonstrated power density and energy density can be found in the table below. As such, it is exceptionally high and superior to all known solid-state intercalated batteries. there was. In addition, these cells are Na/β alumina/S cells (350°C), Li/ Operates at very high temperatures such as LiC1/KCI/FeS2 cells (450°C), etc. The performance is better than that of other cells.

table Storage battery theoretical energy actual energy volume power power density Th/k g Density Th/kg Energy Archive Density Density Simple/I W/kg W/I Li/PEO/1000 300 280 160 144 (SR 3), (OCv=3.0) 264 350350 at 0.5mA/cm' cycle cycle 1 cycle 5 minutes 100% util.

Li/PEO/480 120 150 100 1500 In Figure 2, I/PE Comparison data of O/X and 1/PEO/Tl32 is shown in a graph. graph In the figure, Jc indicates a cell under charge and JD indicates a cell under discharge. Compile the exam Computer controlled and prints peaks during short off time did. Therefore, the true data line is smoothed out by these peaks. thing off). As shown in the graph, the cell of the present invention maintained their voltage well during the discharge period, whereas the comparison cells dropped quickly. did. In addition, the cell of the present invention could be recharged from near 100% utilization of the cathode. .

From the foregoing description, it is clear that the present invention is based on the currently known and used highly developed Provides high specific energy and power cells that exceed the specific energy and power of the system I understand that. At the same time, high energy and power is required for room temperature or ambient temperature operation. Available.

international search report

Claims (15)

[Claims] 1. In charging state, Metal negative electrode; Formula (SRSr) n (wherein y is 2 to 6, n is greater than 2, and R is 1 to one or more different aliphatic or aromatic moieties having 20 carbon atoms; , these moieties contain one or more oxygen when R contains one or more aromatic rings, may contain phosphorus, silicon, sulfur or nitrogen heteroatoms or R is an aliphatic chain. containing one or more oxygen, phosphorus, silicon, sulfur, or nitrogen associated with the chain. or may contain a fluorine atom, and the aliphatic group may be linear or branched. may be saturated or unsaturated, and aliphatic chains or aromatic rings may be The organic sulfur anode material may have a substituent, and the organic sulfur anode material exhibits sulfur when in a charged state. It is further characterized by a yellow-sulfur bond, which breaks down after the cell discharges and leaves the cell. solids containing mainly polymers with metal ions and organometallic salts) organic sulfur anode in body state; and A solid electrolyte is sandwiched between the negative electrode and the anode and is capable of transporting cations between the electrodes. A cell for manufacturing a secondary battery, comprising: 2. If the negative electrode is sodium or lithium or a mixture of metals (sodium or The cell for manufacturing a secondary battery according to claim 1, which contains lithium as a main component. . 3. For manufacturing a secondary battery according to claim 2, wherein the negative electrode mainly contains sodium. cell. 4. Claim 1, wherein the electrolyte is a doped polyalkylene oxide. Cells listed in section. 5. Electrolyte is polyethylene oxide doped with lithium triflate The cell according to claim 4. 6. 6. The cell of claim 5, wherein the anode comprises 0% to about 10% carbon particles. . 7. Claims wherein the anode comprises 0% to about 70% polyalkylene oxide polymer Cell according to paragraph 6. 8. In charging state, Metal negative electrode; Formula (SRSr)n (wherein y is 2 to 6, n is greater than 20, and R is 1 one or more different aliphatic or aromatic moieties having ~20 carbon atoms and these moieties contain one or more oxygen atoms when R contains one or more aromatic rings. , phosphorus, silicon, sulfur or nitrogen heteroatoms, or R is aliphatic. If it contains a chain, one or more oxygen, phosphorus, silicon, sulfur, or nitrogen atoms associated with the chain. may contain elementary or fluorine atoms, and aliphatic groups may be linear or may be branched, saturated or unsaturated, aliphatic chains or aromatic rings may have a substituent, and when the organic sulfur anode material is in a charged state, It is further characterized by a sulfur-sulfur bond, which is broken down after the cell discharges. (forms metal ions and organometallic salts in the cell) a solid state organosulfur anode; and A solid electrolyte is sandwiched between the negative electrode and the anode and is capable of transporting cations between the electrodes. and wherein the electrolyte includes an organic polymer and an electrolyte salt. Cell for pond production. 9. For manufacturing a secondary battery according to claim 8, wherein the negative electrode mainly contains sodium. cell. 10. Manufacture of a secondary battery according to claim 8, wherein the negative electrode substantially consists of lithium. Cell for use. 11. The solid electrolyte is polyethylene oxide doped with sodium triflate. oxide, and the anode contains a small amount of carbon particles. Cells for manufacturing next-generation batteries. 12. The anode has an absolute amount of polyalkylene oxide polymer ranging from 0% to about 70%. 12. A cell for manufacturing a secondary battery according to claim 11. 13. Claim No. 1 in which the polyalkylene oxide is polyethylene oxide The cell for manufacturing a secondary battery according to item 12. 14. In a secondary battery cell that has a metal negative electrode and all components function in a solid state. and the anode comprises from about 0% to about 70% by weight of an inert polymeric material, from about 0% to about 10% by weight carbon particles, and about 30% to about 100% by weight active material. It is highly polymeric in the charged state and frees metals and salts from the negative electrode in the discharged state. ), and said active material in a charged state has the formula (SRSr)n, where y is 2 to 6, n is greater than 20, and R is one or more having 1 to 20 carbon atoms. different aliphatic or aromatic moieties above, these moieties include one or more R aromatic ring, one or more oxygen, phosphorus, silicon, sulfur or nitrogen atoms. may contain a terroratom or, if R contains an aliphatic chain, be associated with that chain. It may also contain one or more oxygen, phosphorus, silicon, sulfur, nitrogen or fluorine atoms. , aliphatic groups may be linear or branched, saturated or unsaturated. The aliphatic chain or aromatic ring may have a substituent, and the aliphatic chain or aromatic ring may have a substituent. The organosulfur anode material is further characterized by sulfur-sulfur bonds when in the charged state. This bond is broken down after the cell discharges, producing metal ions and organometallic salts in the cell. 1. A secondary battery cell characterized by having: 15. Claim 14 wherein the inert polymeric material is polyethylene oxide. Cells described in.