Designing 3D SnS@Cu-Ni Nanoporous Column Array Electrode for High-Capacity and High-Rate Lithium-Ion Batteries

Sn-based materials with high capacity showcase great potential for next-generation lithium-ion batteries (LIBs). Yet, the large volume change and limited ion/electron transfer efficiency of Sn-based materials upon operation significantly compromises the battery performance. In this study, a unique 3D copper-nickel nanoporous column array current collector is rationally developed via a facile template-free galvanostatic electrodeposition method, followed by electrodepositing SnS active material onto it (denoted as 3D SnS@CNCA). Excitingly, the morphology of the 3D SnS@CNCA electrode perfectly inherited the nanoporous column array structure of the 3D current collector, which not only endows the electrode with a large specific surface area to provide more active sites and sufficient ion/electron transport pathways, but also effectively alleviates the volume expansion of SnS upon repeated charge-discharge cycles. Therefore, the binder-free 3D SnS@CNCA electrode showcases a significantly enhanced Li storage performance, showing a high initial reversible capacity of 1019.7 mAh g^-1 with noteworthy cycling stability (a capacity retention rate of 89.4% after 200 cycles). Moreover, the designed electrode also manifests high rate performance with a high capacity of 570.6 mAh g^-1 at 4 A g^-1. This work provides a novel design idea for the preparation of high-performance electrodes beyond LIBs.