π-π stacking of unsaturated sulfonates on natural graphite enables a green and cost-effective cathode for high-voltage dual-ion batteries

A sustainable and cost-effective energy storage system is the research focus at present and also the development direction of the future. A green and cost-effective cathode material for high-voltage dual-ion batteries (DIBs) is presented in this work through the artificial implantation of unsaturated organic sulfonates on the surface of natural graphite (NG) particles via a low-cost and green synthesis route. It is interesting to discover and validate that pi-pi stacking interactions exist between the pi-bonds of unsaturated sulfonates and graphite layers through both practical experiments and density functional theory simulations. The C0000000000000000000000000000000000000000000000000000111111111111111000000000000000000011111111111111100000000000000000001111111111111110000000000000000000000000000000000000000000000000000C bond-containing propyne sulfonate (PyS) exhibits stronger pi-pi stacking interactions on graphite layers than the C00000000000000000000000000000000111111110000000011111111000000000000000000000000C bond-containing allyl sulfonate and C-C bond-containing propane sulfonate. The PyS layer works as an artificial and highly stable cathode/electrolyte interphase (CEI), which effectively precludes electrolyte decomposition, reduces interfacial resistance and protects the NG cathode from structural degradation. The as-prepared NG@PyS exhibits outstanding cycling performance as the cathode material of DIBs by virtue of the high adhesion capability of PyS on graphite. A green and cost-effective material for dual-ion batteries is obtained by virtue of pi-pi stacking between unsaturated sulfonates and graphite.

Automated summary

This study presents a green and cost-effective cathode material for high-voltage dual-ion batteries, achieved through the implantation of unsaturated organic sulfonates on the surface of natural graphite. The material shows strong cycling performance and stability, effectively protecting the battery structure and reducing interfacial resistance.