Preferential Pyrolysis Construction of Carbon Anodes with 8400 h Lifespan for High-Energy-Density K-ion Batteries

Carbonaceous materials are promising anodes for practical potassium-ion batteries, but fail to meet the requirements for durability and high capacities at low potentials. Herein, we constructed a durable carbon anode for high-energy-density K-ion full cells by a preferential pyrolysis strategy. Utilizing S and N volatilization from a pi-pi stacked supermolecule, the preferential pyrolysis process introduces low-potential active sites of sp(2) hybridized carbon and carbon vacancies, endowing a low-potential vacancy-adsorption/intercalation mechanism. The as-prepared carbon anode exhibits a high capacity of 384.2 mAh g(-1) (90 % capacity locates below 1 V vs. K/K+), which contributes to a high energy density of 163 Wh kg(-1) of K-ion full battery. Moreover, abundant vacancies of carbon alleviate volume variation, boosting the cycling stability over 14 000 cycles (8400 h). Our work provides a new synthesis approach for durable carbon anodes of K-ion full cells with high energy densities.

Automated summary

A durable carbon anode for high-energy-density potassium-ion full cells was constructed using a preferential pyrolysis strategy. By utilizing volatilization of S and N from a pi-pi stacked supermolecule, the anode introduced low-potential active sites of sp(2) hybridized carbon and carbon vacancies, resulting in a low-potential vacancy-adsorption/intercalation mechanism. The as-prepared carbon anode exhibited a high capacity of 384.2 mAh g(-1) (with 90% capacity below 1 V vs. K/K+) and a high energy density of 163 Wh kg(-1) in the potassium-ion full battery. Moreover, the abundant vacancies of carbon improved cycling stability over 14,000 cycles (8,400 hours). This work provides a new synthesis approach for durable carbon anodes with high energy densities in potassium-ion full cells.