Improvement of lithium storage performance of Sn-alloy anode materials by a polypyrrole protective layer

The SnO 2 -based anode with improved reversible capacity and cyclability was achieved by employing a protective layer composed of crosslinked polypyrrole nanowires. Scanning electron microscopy measurement was performed to characterize the surface and cross section morphology of electrodes before and after cycling. The crosslinked polypyrrole nanowire protective layer with good elasticity adhered to the SnO 2 surface could form a network, leading to buffer the volumetric swelling of active materials during the lithiation/delithiation process. A good cycling stability and an excellent rate capability of the modified electrode were achieved.