Melamine Polymerization Promotes Compact Phosphorus/Carbon Composite for High‐Performance and Safe Lithium Storage

Abstract

Phosphorus is regarded as a promising material for high‐performance lithium‐ion batteries (LIBs) due to its high theoretical capacity, appropriate lithiation potential, and low lithium‐ion diffusion barrier. Phosphorus/carbon composites (PC) are engineered to serve as high‐capacity high‐rate anodes; the interaction between phosphorus and carbon, long‐term capacity retention, and safety problems are important issues that must be well addressed simultaneously. Herein, an in situ polymerization approach to fabricate a poly‐melamine‐hybridized (pMA) phosphorus/carbon composite (pMA‐PC) is employed. The pMA hybridization enhances the density and electrical conductivity of the PC, improves the structural integrity, and facilitates stable electron transfer within the pMA‐PC composite. Moreover, the pMA‐PC composite exhibits efficient adsorption of lithium polysulfides, enabling stable transport of Li+ ions. Therefore, the pMA‐PC anode demonstrates a high specific charging capacity of 1,381 mAh g−1 at 10 A g−1, and a great capacity retention of 86.7% at 1 A g−1 over 500 cycles. The synergistic effect of phosphorus and nitrogen further confers excellent flame retardant properties to the pMA‐PC anode, including self‐extinguishing in 2.5 s, and a much lower combustion temperature than PC. The enhanced capacity and safety performance of pMA‐PC show potential in future high‐capacity and high‐rate LIBs.