N-Doped gel-structures for construction of long cycling Si anodes at high current densities for high performance lithium-ion batteries

Abstract

In this work, we design an effective and controllable strategy to synthesize an interconnected conductive network skeleton SNGC-gel structure. When used as a lithium-ion battery anode, the SNGC-gel structure material possesses a long cycling life of more than 3000 cycles at high current densities (494.5 mA h g⁻¹ at 10 A g⁻¹ and 366.8 mA h g⁻¹ at 20 A g⁻¹), showing extraordinary performance. Meanwhile, the SNGC-gel electrode exhibits a stable reversible specific capacity of 1480.3 mA h g⁻¹ at a large current density of 2 A g⁻¹ after 400 cycles. In addition, the storage of charge by diffusion control and capacitance control is further explored. At high current densities, the contribution of capacitance control to capacity is of great significance. The electrochemical performance of the prepared SNGC-gel electrode is so impressive that it has the potential to be the anode material for the next generation of lithium ion batteries.