Yolk–Shell P3‐Type K<sub>0.5</sub>[Mn<sub>0.85</sub>Ni<sub>0.1</sub>Co<sub>0.05</sub>]O<sub>2</sub>: A Low‐Cost Cathode for Potassium‐Ion Batteries
Jiaxin Hao, Ke Xiong, Jiang Zhou, Apparao M. Rao, Xianyou Wang, Huan Liu, Bingan Lu
Abstract
Low‐cost preparation methods for cathodes with high capacity and long cycle life are crucial for commercializing potassium‐ion batteries (PIBs). Presently, the charging/discharging strain that develops in the active cathode material of PIBs causes cracks in the particles, leading to a sharp capacity fade. Here, to abate the strain release and the need for an industrially relevant process, a simple low‐cost co‐precipitation method for synthesizing yolk–shell P3‐type K 0.5 [Mn 0.85 Ni 0.1 Co 0.05 ]O 2 (YS‐KMNC) was reported. As cathode material for PIBs, the YS‐KMNC delivers a high reversible capacity (96 mAh g –1 at 20 mA g –1 ) and excellent cycle stability (80.5% retention over 400 cycles at a high current density of 200 mA g –1 ). More importantly, a full battery assembled with the YS‐KMNC cathode and a commercial graphite anode exhibits a high operating voltage (0.5‐3.4 V) and an excellent cycling performance (84.2% retention for 100 cycles at 100 mA g –1 ). Considering the low‐cost, simple production process and high performance of YS‐KMNC cathode, this work could pave the way for the commercial development of PIBs.