KOH-treated mesocarbon microbeads used as high-rate anode materials for potassium-ion batteries

Graphite is one of the most promising anode materials for potassium-ion batteries (PIBs) due to its low cost and stable discharge plateau. However, its poor rate performance still needs to be improved. A novel graphitic anode was designed from com-mercial mesocarbon microbeads (MCMBs) by KOH treatment. Using limited oxidation and slight intercalation, the interlayer spa-cing of graphitic layers on the surface of the MCMBs was increased, causing the K+ diffusion rate to be significantly improved. When this modified material was combined with carboxymethyl cellulose as a binder (79.2％) and used as a PIB anode, it had a high plateau capacity below 0.25 V (271 mAh g?1), superior rate capability (160 mAh g?1 at 1.0 A g?1), excellent cycling stability (about 184 mAh g?1 after 100 cycles at 0.1 A g?1), and a high initial coulombic efficiency. This work provides a simple strategy to prepare graphitic materials with an excellent potassium storage performance.