A like-bulletproof glass structure flexibility-rigidity coating layer strategy for high-performance Li ion batteries Si anodes

Abstract

In order to overcome the problems about the volume expansion and poor electronic conductivity of Si, a flexibility and rigidity double coating layer CNTs-rGO- PAIN was constructed. The CNTs-rGO-PANI network with porous structure and high electronic conductivity provides sufficient space to accommodate the volume change of Si, and abundant transmission path for electron and Li ion. Moreover, the coating network with flexibility and rigidity characteristic could absorb the expansion stress of Si, maintain electrode structural integrity, promote the growth of stable SEI. The polymer-nanocarbon network dual coating layer effectively safeguards the electrochemical-mechanical interplay within the electrode. The 20Si-CNTs-rGO-PANI exhibits a reversible capacity as high as 1856 mAh g⁻¹ after 400 cycles at 0.2 A g⁻¹ and a remarkable rate capacity of 570 and 459 mAh g⁻¹, at 5 and 10 A g⁻¹, respectively. The outstanding Li ion storage performance of 20Si-CNTs-rGO-PANI anode, suggests the flexibility-rigidity dual coating layer strategy is a potential way to improve the performance of alloy type anode.