Designing SnOx/C films via co-sputtering as anodes for all-solid-state batteries

Abstract

Abstract SnO x /C composite thin films were deposited on stainless steel disc substrates by radio frequency magnetron co-sputtering. SnO x /C thin film anode samples with different tin oxide and carbon ratios were electrochemically investigated. Samples with high carbon composition showed high capacity retention and stability compared to SnO 2 -only thin film anodes. The film with high carbon content delivered an initial discharge capacity of 8990 mA h cm − 3 at a current density of 150 μA cm − 2 . In the rate capability test from 50 to 500 μA cm − 2 , the last cycle showed 58% of the 1st cycle capacity, while the other samples retained below 50% of the initial capacity. These results indicate that carbon in the thin films resulted in electric conductivity and acted as a buffer for the detrimental tin oxide volume expansion. Consequently, co-sputtering of tin oxide and carbon opens up the possibility of non-lithium anode materials. Moreover, these SnO x /C thin films can be applied as high-performance anode materials for all-solid-state batteries.