Nickel-catalyzed CNTs enhancing cycle performance of Si@C anodes

Abstract

The drastic volume change and interfacial instability during repeated cycles are the main obstacles hindering the practical application of silicon anodes. Micro/nano core–shell structures with nickel supports were constructed by spray drying and chemical vapor deposition (CVD) for silicon–carbon anode materials. The catalysis of nickel drives the growth of multidirectionally interconnected CNTs. This three-dimensional electron transport network effectively dissipates mechanical stress and increases the Li⁺ diffusion rate. At the same time, the outer dense carbon coating can inhibit the continuous reduction of electrolyte, which is beneficial to the formation of a thin and uniform SEI. The built micro/nano core–shell structure with a three-dimensional conductive network offers the possibility to alleviate the volume expansion of silicon and stabilize the electrode/electrolyte interface. Therefore, the modified sample maintained a reversible capacity of 1265 mAh g⁻¹ at 2 A g⁻¹ after 400 cycles and exhibited an excellent rate capability at 6 A g⁻¹ (1023 mAh g⁻¹). This unique micro/nano core–shell structure provides a feasible technical route for constructing highly stable silicon/carbon anodes.