Tuning local chemistry of P2 layered-oxide cathode for high energy and long cycles of sodium-ion battery

作者：Chenchen Wang, Luojia Liu, Shuo Zhao, Yanchen Liu, Yubo Yang, Haijun Yu, Suwon Lee, Gi‐Hyeok Lee, Yong‐Mook Kang, Rong Liu, Fujun Li, Jun Chen · 发表于：Nature Communications · 年份：2021 · DOI：10.1038/s41467-021-22523-3 · 被引用次数：481 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、Supercapacitor Materials and Fabrication

Abstract Layered transition-metal oxides have attracted intensive interest for cathode materials of sodium-ion batteries. However, they are hindered by the limited capacity and inferior phase transition due to the gliding of transition-metal layers upon Na + extraction and insertion in the cathode materials. Here, we report that the large-sized K + is riveted in the prismatic Na + sites of P2-Na 0.612 K 0.056 MnO 2 to enable more thermodynamically favorable Na + vacancies. The Mn-O bonds are reinforced to reduce phase transition during charge and discharge. 0.901 Na + per formula are reversibly extracted and inserted, in which only the two-phase transition of P2 ↔ P’2 occurs at low voltages. It exhibits the highest specific capacity of 240.5 mAh g −1 and energy density of 654 Wh kg −1 based on the redox of Mn 3+ /Mn 4+ , and a capacity retention of 98.2% after 100 cycles. This investigation will shed lights on the tuneable chemical environments of transition-metal oxides for advanced cathode materials and promote the development of sodium-ion batteries.