High-Performance B-Doped Na<sub>0.44</sub>MnO<sub>2</sub> Cathode Materials for Sodium-Ion Batteries
Zhen Ming Liu, Xing Ting Feng, Hai Jun Zhao, X. Han, Zi Ye, Zhidong Yao, Ding Zhang
Abstract
High Resolution Image Download MS PowerPoint Slide Na 0.44 MnO 2 (NMO) is a promising cathode material for sodium-ion batteries (SIBs) due to its unique tunnel structure and derived sodium storage property. In this study, we prepared the doped cathode material Na 0.44 Mn 0.98 B 0.02 O 2 (NMOB 0.02 ) and observed that introducing optimal B improves electrochemical stability and air stability. The prepared Na 0.44 Mn 0.98 B 0.02 O 2 material releases an initial reversible specific capacity of 100.5 mAh g –1 at 0.2 C (1 C = 120 mA g –1 ). Compared with the undoped material, the capacity retention rate increases from 69.8 to 86.8% after 350 cycles at 1 C, and this parameter evaluated at 50 °C increases from 63.6 to 88.9% after 100 cycles at 1 C. Both electrochemical impedance spectra (EIS) and GITT test results show that the proper B doping is capable of promoting the diffusion of Na +, and the in situ X-ray diffraction (XRD) technique was employed to demonstrate the high reversibility of NMOB 0.02 during the charge and discharge processes. This study provides a helpful reference for other researchers to design and optimize cathode materials for sodium-ion batteries with excellent thermal stability.