Fast and Stable Charge Transfer Reaction at the Li_(4/3)Ti_(5/3)O_4/Lithium Phosphorus Oxynitride (LiPON) Interface and its Application to All-Solid-State Thin Film Batteries

摘要

Electrochemical lithium insertion/extraction properties at Li_4Ti_5O_(12) thin film/lithium phosphorus oxynitride glass electrolyte (LiPON) were investigated using thin film batteries (Li/LiPON/Li_(4/3)Ti_(5/3)O_4). The resultant battery performed very stable charge-discharge reactions for over 300 times. In addition, the rate capability under 4-40 μA cm~(-2) of the film battery was comparable with that of the film electrode in 1 mol dm~(-3) LiCl_4 dissolved in propylene carbonate solution. Using the Li_(4/3)Ti_(5/3)O_4 thin film as negative electrode material, all-solid-state thin-film lithium-ion batteries (Li_(4/3)Ti_(5/3)O_4/LiPON/amorphous lithium iron phosphate) were fabricated, where the Li_(4/3)Ti_(5/3)O_4 thin film was embedded in LiPON film. This unique assembly permitted charge-discharge reactions at ca. 1.5 V also in air.