Isotropic high softening point petroleum pitch-based carbon as anode for high-performance potassium-ion batteries

Abstract

Soft carbon materials are considered as promising anodes for potassium-ion batteries (KIBs) due to their low cost, ease of available, excellent electronic conductivity and tunable interlayer distance. However, they still exhibit unsatisfying performance for K-ions storage owing to the serious volume expansion and sluggish kinetics when forming potassium intercalation compounds. To date, the bulk soft carbon anodes for outstanding capacity of potassium storage have been rarely studied. Herein, a unique bulk soft carbon has been synthesized via a facile pyrolysis method, which shows a high reversible capacity of 343.2 mA h g−1, excellent rate capability, and good cycling performance (a retention of 86.2% at 100 mA g−1 after 100 cycles). The soft carbon with larger interlayer spacing and moderate defects can not only facilitate ion diffusion but also provide active sites for K-ions storage, contributing to an outstanding capacity and excellent rate performance. In addition, full cells constructed with the obtained soft carbon as anode also exhibit a good performance with a capacity of 201 mA h g−1. Considering the cost issue, practical application and electrochemical performance, this work provides a strategy for manufacturing low cost and brilliant electrochemical performance KIBs anode material.