Thin film microbattery anodes, the tin oxide films with different amounts of Si addition (5,10,15
mol%), were prepared with e-beam evaporation at room temperature to improve both cycle performance
and reversible capacity. The effect of Si addition to the SnO2 thin film on structural change
and electrochemical performance was investigated. The deposited films at room temperature were
ill-de ned and featureless. However, cycled films showed aggregated tin particles and formation of
cracks, which induce cell failure. When 5 mol% Si is doped, the film effectively hinders growth of
tin grains and cracks. Increments of Si addition affect the increasing of Si-O bonding density and
reducing reduction of Sn-O bonds. The amounts of Si dopants were critical, and all of the Si doped
films show better cycle behavior than the undoped films. The 5 mol% Si doped SnO2 film especially
exhibited the highest reversible capacity of about 200uAh/cm2 - um over 50 cycles. Furthermore,
doping of the optimized Si amount to the SnO2 films resulted in reduction of mechanical cracking
during cycling.
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