Fabrication of a flexible lithium-ion battery on stainless steel by radio-frequency magnetron sputtering

摘要

Flexible all-solid-state rechargeable lithium ion batteries were successfully fabricated on 70 μm thick, flexible stainless steel (SS304) substrates. Each cell of the battery consisted of a thin film lithium metal anode, LiPON solid electrolyte, and a thin film LiMn_2O_4 cathode that was deposited by radio frequency magnetron sputtering at room temperature. Electrochemical characterization of this flexible lithium-ion battery revealed a discharge capacity of 12.8 μAh between 4.3V and 3V at a current density of 5 μA/cm~2 (0.5C). A maximum capacity retention in excess of 85 % was also achieved after 200 charge-discharge cycles between 4.2V and 3V at a current density of 10 μA/cm~2 (1C). This flexible lithium-ion battery also exhibits a high C-rate performance, with a capacity retention of 83% at 50 μA/cm~2 (5C) and 73% at 200 μA/cm~2 (20C).