Thin film battery and electrolyte therefor
AssigneeOak Ridge Micro-Energy, Inc.
InventorJohn B Bates
Life of this patent
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Abstract
A solid amorphous electrolyte composition for a thin-film battery. The electrolyte composition includes a lithium phosphorus oxynitride material containing a sulfide ion dopant wherein the atomic ratio of sulfide ion to phosphorus ion (S/P) in the electrolyte ranges greater than 0 up to about 0.2. The composition is represented by the formula: LiwPOxNySz, where 2x+3y+2z=5+w, x ranges from about 3.2 to about 3.8, y ranges from about 0.13 to about 0.46, z ranges from greater than zero up to about 0.2, and w ranges from about 2.9 to about 3.3. Thin-film batteries containing the sulfide doped lithium oxynitride electrolyte are capable of delivering more power and energy than thin-film batteries containing electrolytes without sulfide doping.
Claims22
A solid amorphous electrolyte composition for a thin-film battery comprising a lithium phosphorus oxynitride material containing a sulfide ion dopant wherein the atomic ratio of sulfide ion to phosphorus ion (S/P) in the electrolyte ranges from greater than 0 up to about 0.2 and wherein the composition is represented by the formula:
- LiwPOxNySz,
- where 2x+3y+2z=5+w, x ranges from about 3.2 to about 3.8, y ranges from about 0.13 to about 0.46, z ranges from greater than zero up to about 0.2, and w ranges from about 2.9 to about 3.3.
A method for making a solid electrolyte for a thin-film battery comprising the steps of:
- providing a lithium orthophosphate (Li3PO4) composition;
- providing a lithium ion and sulfide ion containing component selected from the group consisting of Li2SO4 and Li2S;
- combining the lithium orthophosphate powder and the lithium ion and sulfide ion containing powder to provide a sputtering target;
- sputtering the target in a gas atmosphere selected from nitrogen gas, argon gas, and mixtures of nitrogen and argon gases to provide an electrolyte film having a composition represented by the formula:
- LiwPOxNySz,
- where 2x+3y+2z=5+w, x ranges from about 3.2 to about 3.8, y ranges from about 0.13 to about 0.46, z ranges from greater than zero up to about 0.2, and w ranges from about 2.9 to about 3.3, and wherein the ratio of sulfide ion to phosphorus ion (S/P) ranges from greater than 0 up to about 0.2.
A method for making a sulfide-doped solid lithium phosphorus oxynitride electrolyte for a thin-film battery comprising the steps of:
- providing a lithium orthophosphate (Li3PO4) composition as a sputtering target;
- sputtering the target in an atmosphere containing nitrogen gas and hydrogen sulfide gas wherein the mixture of nitrogen gas and hydrogen sulfide gas in the atmosphere is represented by the following:
- (1−t)N2+tH2S,
- where t is greater than 0 and less than 1 to provide an electrolyte film having a composition represented by the formula:
- LiwPOxNySz,
- where 2x+3y+2z=5+w, x ranges from about 3.2 to about 3.8, y ranges from about 0.13 to about 0.46, z ranges from greater than zero up to about 0.2, and w ranges from about 2.9 to about 3.3, and wherein the ratio of sulfide ion to phosphorus ion (S/P) ranges from greater than 0 up to about 0.2.
Dependencies are inferred from the claim text.