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 an aluminum ion dopant wherein the atomic ratio of aluminum ion to phosphorus ion (Al/P) in the electrolyte ranges greater than zero up to about 0.5. The composition is represented by the formula: LitPxAlyOuNvSw, where 5x+3y=5, 2u+3v+2w=5+t, t ranges from about 2.9 to about 3.3, x ranges from about 0.94 to about 0.85, y ranges from about 0.094 to about 0.26, u ranges from about 3.2 to about 3.8, v ranges from about 0.13 to about 0.46, and w ranges from zero to about 0.2. Thin film batteries containing such electrolyte films have less tendency to fail prematurely.
Claims24
A solid amorphous electrolyte composition for a thin-film battery comprising a lithium phosphorus oxynitride material containing an aluminum ion dopant, wherein the atomic ratio of aluminum ion to phosphorus ion (Al/P) in the electrolyte ranges from greater than zero up to about 0.5, and wherein the composition is represented by the formula:
- LitPxAlyOuNvSw,
- where 5x+3y=5, 2u+3v+2w=5+t, t ranges from about 2.9 to about 3.3, x ranges from about 0.94 to about 0.85, y ranges from about 0.094 to about 0.26, u ranges from about 3.2 to about 3.8, v ranges from about 0.13 to about 0.46, and w ranges from zero to about 0.2.
A method for making a solid electrolyte for a thin-film battery comprising the steps of:
- providing a lithium orthophosphate (Li3PO4) composition;
- providing an aluminum ion source, and, optionally, a sulfide ion source;
- combining the lithium orthophosphate composition, aluminum ion source, and, optional sulfide ion source to yield 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:
- LitPxAlyOuNvSw,
- where 5x+3y=5, 2u+3v+2w=5+t, t ranges from about 2.9 to about 3.3, x ranges from about 0.94 to about 0.85, y ranges from about 0.094 to about 0.26, u ranges from about 3.2 to about 3.8, v ranges from about 0.13 to about 0.46, and w ranges from zero to about 0.2, and wherein the ratio of aluminum ion to phosphorus ion (Al/P) ranges from greater than zero up to about 0.5.
A method for making an aluminum-doped solid lithium phosphorus oxynitride electrolyte for a thin-film battery comprising the steps of:
- providing a lithium orthophosphate (Li3PO4) composition and an aluminum ion source 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−z)N2+zH2S,
- where z is greater than 0 and less than 1 to provide an electrolyte film having a composition represented by the formula:
- LitPxAlyOuNvSw,
- where 5x+3y=5, 2u+3v+2w=5+t, t ranges from about 2.9 to about 3.3, x ranges from about 0.94 to about 0.85, y ranges from about 0.094 to about 0.26, u ranges from about 3.2 to about 3.8, v ranges from about 0.13 to about 0.46, and w ranges from zero to about 0.2.
Dependencies are inferred from the claim text.