Facile construction of honeycomb-shaped porous carbon electrode materials using recyclable sodium chloride template for efficient lithium storage

Carbon materials are the preferred anode materials for Li-ion batteries. Here, we propose an easy and sustainable strategy to prepare honeycomb-shaped porous carbon (HPC) electrode materials through a process involving simple calcination and subsequent water washing by using polyvinyl-pyrrolidone (PVP) as carbon source and NaCl as pore-forming agent. A controllable cavity size and distribution of the carbon materials can be readily obtained solely by adjusting the NaCl amount. Results showed that the optimized HPC sample had a relatively uniform cavity distribution and a highly porous structure. Moreover, the special honeycomb-shaped structure was conducive to the electronic conductivity of the electrode materials, provided a short path for Li-ion transport and a wide interface with the electrolyte, and buffered the volume change of active materials. The special honeycomb-shaped structure was also maintained well after long cycles, which improved electrode stability. When used as anode materials for Li-ion batteries (LIBs), the sample demonstrated excellent cycling stability and rate performance, with a high specific capacity of 230 mA h g−1 and a reversible capacity of 197 mA h g−1, after 1200 cycles at 2 C. Overall, we introduced a simple strategy for the potential mass production of porous carbon materials for LIBs.