Solid electrolyte and batteries
OwnerEmanuel Peled, Diana Golodnitsky +2inventors
InventorsEmanuel Peled, Diana Golodnitsky, Ronen Cohen, Chen Menachem
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Abstract
A composite solid electrolyte having a transference number above 0.5 for use in primary or secondary electrochemical cells. The solid electrolyte includes non-conductive oxide particles, of less than 5 microns in size, an alkali metal salt coating or in contact with these particles, an insulating elastomer forming a complex with the salt, and a solvent. Batteries and multi-cell batteries contain such solid electrolyte, and such batteries can be assembled with the cathod in the discharged state.
Claims16
A composite solid electrolyte (CSE), for use in electrochemical cells, said CSE having an alkali metal transference number larger than about 0.5, wherein said CSE consists of:
- from 1 to about 40 volume-% electronically non-conductive oxide particles of an average size of less than about 5.mu., which are compatible with alkali metals,
- 10 to 80 volume-% of an alkali metal salt MX, where M is an alkali metal and X an anion, which salt forms a thin coating on said oxide particles or is in contact with said oxide particles, which salt MX is not reducible by the alkali metal in said cell,
- about 5 to about 80 volume-% of an electronically insulating elastomer, including a hydrocarbyl polymer, which elastomer forms a complex with the alkali metal salt, and
- up to 20 volume-% of an aprotic organic solvent of low MW polymer, having a molecular weight of up to 5000, which polymer serves as plasticizer, excluding a system of polyethylene oxide (PEO), LiI and Al.sub.2 O.sub.3 only.
A primary or secondary electrochemical battery which battery comprises a composite solid electrolyte wherein said composite solid electrolyte consists of:
- 3 to 40 volume-% electronically non-conductive oxide particles of an average size of less than about 5.mu., which are compatible with alkali metals,
- 5 to 80 volume-% of an alkali metal salt MX, where M is an alkali metal and X an anion, which salt forms a thin coating on said oxide particles or is in contact with said oxide particles, which salt MX is not reducible by the alkali metal in said cell,
- 10 to 80 volume-% of an electronically insulating elastomer forms a complex with the alkali metal salt, and
- 2 to 20 volume-% of an aprotic organic solvent of low MW polymer, having a molecular weight of up to 5000, which polymer serves as plasticizer, excluding a system of polyethylene oxide (PEO), LiI and Al.sub.2 O.sub.3 only.
A battery consisting of:
- an anode comprising a member selected from the group consisting of alkali metal, alkali metal alloy and M.sub.x C, where M is alkali metal or alkali metal alloy and x<0.2;
- and anode and cathode compatible polymer electrolyte consisting of at least one alkali metal salt in which the cathode can be charged and discharged, an elastomer which can complex said at least one salt;
- and a cathode or composite NiS.sub.x and CoS.sub.x (0.8<x<4.5), where the polymer electrolyte contains oxides of Al, Si, Mg, Ca, Ba, Sr and mixtures thereof, the elastomer optionally contains a polymer selected from the group consisting of PMMA, PMA, PBA PBMA, PAN, a polyalkylene glycol dialkyl ester and ether, and solvent selected from the group consisting of propylene carbonate, ethylene carbonate, butyrolactone, DMSO, diethylene carbonate, THF, 2MTHF, dioxolane, DME and mixtures thereof, with the preferred M being Li.
A secondary battery consisting of:
- an alkali metal or alkali metal alloy of M.sub.x C (where M is alkali metal or alkali metal alloy and .sub.x <0.2) anode;
- an anode and cathode compatible polymer composite solid electrolyte consisting of an alkali metal salt in which the cathode can be charged, an elastomer which can complex said salt;
- and a cathode or composite cathode which comprises a member selected from the group consisting of FeS.sub.2, FeS, NiS.sub.x, And CoS.sub.x (0.8<.sub.x <4.5), where the polymer electrolyte contains oxides of Al, Si, Mg, Ca, Ba, Sr and mixtures thereof, and the elastomer optionally contains a polymer selected from the group consisting of PMMA, PMA, PBA, PBMA, PAN, a polyalkylene glycol dialkyl ester and ether, and solvent selected from the group consisting of propylene carbonate, ethylene carbonate, butyrolactone, DMSO diethylene carbonate, THF, 2MTHF, dioxolane, DME and a mixture thereof, with the preferred M being Li.
Dependencies are inferred from the claim text.