Performance of Sn-based Negative Electrode Films Prepared by Electrostatic Spray Deposition in Lithium Batteries

SnO2 and CuSnO2 were successfully sprayed onto a Ni substrate using electrostatic spray deposition to produce negative electrode films with highly porous morphologies for use in lithium batteries. The spray-deposited SnCl2 decomposed to Sn during heat treatment at 230°C under inert atmosphere and then was oxidized to SnO2 being exposed to the air. The resultant SnO2 film, which did not contain any additives such as binders or conductive additives, was used as a negative electrode. At the beginning of some charge-discharge cycles, the SnO2 film achieved a capacity of 780 mAh g−1, which was close to its theoretical capacity. However, its capacity subsequently decreased because of crystal growth during the Li alloying-dealloying process. The capacity retention of the film was improved by adding Cu to the precursor solution. Although the initial capacity of the CuSnO2 film was lower than that of the SnO2 film, the CuSnO2 film displayed better cycle performance; i.e., it possessed more than double the capacity of the SnO2 film after 100 cycles.