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

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

doi:10.1038/s41467-021-22523-3

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

Nat Commun. 2021 Apr 15;12(1):2256. doi: 10.1038/s41467-021-22523-3.

Authors

Chenchen Wang¹, Luojia Liu¹, Shuo Zhao¹, Yanchen Liu¹, Yubo Yang², Haijun Yu², Suwon Lee³, Gi-Hyeok Lee^{4

5}, Yong-Mook Kang³, Rong Liu⁶, Fujun Li⁷, Jun Chen¹

Affiliations

¹ Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin, China.
² College of Materials Science and Engineering, Beijing University of Technology, Beijing, China.
³ Department of Materials Science and Engineering, Korea University, Seoul, Republic of Korea.
⁴ Department of Materials Science and Engineering, Dongguk University, Seoul, Republic of Korea.
⁵ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
⁶ Secondary Ion Mass Spectrometry Facility, Western Sydney University, Locked 17 Bag 1797, Penrith, NSW, Australia.
⁷ Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin, China. fujunli@nankai.edu.cn.

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_0.612K_0.056MnO₂ 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 Mn³⁺/Mn⁴⁺, 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.