Flexible anodic SnO2 nanoporous structures uniformly coated with polyaniline as a binder-free anode for lithium ion batteries

Herein we report a wet-chemical process to obtain binder-free anodes for lithium-ion batteries (LIBs) using a straightforward and easily scalable approach. Electrochemical deposition, anodization, and electropolymerization are used to firmly attach a nanoporous and flexible SnO2 film, uniformly coated with polyaniline (PANI), onto a Cu substrate. The three-dimensional, flexible, and nanoporous SnO2@PANI electrodes exhibit good specific capacity, capacity retention, and charge transfer resistance. Its favorable electrochemical properties are attributed to the large surface area, high electrical conductivity, and effective reduction of volume expansion. These results demonstrate that the proposed approach to forming SnO2@PANI electrodes is a promising strategy for constructing high-performance binder-free anodes for emerging flexible LIBs.