Characteristics research of electrodeposited Sn-Cu alloy anode for lithium ion battery

A thin film of active tin that can reversibly react with lithium was electrodeposited onto a copper foil collector and employed as anode for lithium ion battery after a heat-treatment in argon atmosphere. The analysis results of scanning electron microscopy (SEM), X-ray diffraction (XRD) and electrochemical tests of model cells show that the initial discharge specific capacity of the electrodeposited tin electrode is higher than that of the slurry-coating tin electrode. They are 747 mAh-g^-1 and 442 mAh-g^-1 respectively. The electrode surface structure, chemical composition, and crystal size are different before and after heat-treatment (e.g. tin crystal size: 102.4 nm and 121.0 nm, respectively). Despite of a lower initial discharge specific capacity (4.9 mAh-g^-1), the annealed tin electrode has a much higher initial coulomb efficiency (92%) and more excellent cycle performance (the capacity retention after 30 cycles: 58%) compared with no annealing tin electrode.