PVC-Derived Amorphous Carbon Materials for Sodium Storage Anodes

A soft–hard carbon composite anode is prepared using polyvinyl chloride (PVC), the primary component of plastic waste, as a soft carbon material. In order to solve the inherent problems of small capacity and low first-charge/discharge efficiency of soft carbon, the structural modification of PVC-derived carbon materials is carried out using the composite method for soft and hard carbon materials and the molten salt pore-forming method. The pore formation not only improves the capacity of Na⁺ storage in pores, but also prevents the growth of sodium dendrites and avoids structural collapse when sodium is stored at a low potential platform, which helps to enhance the stability of the structure at high current density. The optimized sample achieves initial coulombic efficiency of 63%, capacity of 276.39 mAh g⁻¹ at 0.05 C (C = 372 mA g⁻¹), and good rate capability (e.g., 131 mAh g⁻¹ at 5 C). Generally speaking, this work not only realizes high-performance carbon material with appealing high-power sodium storage properties, but also opens up a new field of vision for the considerable performance potential of soft carbon-based energy storage electrodes, and provides a reasonable and simple strategy for the recycling of waste plastics.