High-Energy Na-Ion Batteries Using Single-Crystalline Cathode
Zheng Lian, Haibo Wang, Zhao Chen, Chunliu Xu, Hao Yu, Feixiang Ding, Huican Mao, Dan Yu, Yang Yang, Bowen Wang, Lin Zhou, Jiao Zhang, Xiaobing Zhao, Qinghua Zhang, Xiaohui Rong, Xixi Shi, Lianqi Zhang, Yong‐Sheng Hu, Junmei Zhao
Abstract
Owing to the high theoretical capacity, O3-type Ni–Fe–Mn-based layered oxides are one of the cathodes with the greatest potential for high-energy Na-ion batteries (NIBs). However, their poor cycling life and air stability greatly limit their practical application. Herein, we synthesized single-crystalline O3–Na 0.95 Ni 0.4 Fe 0.2 Mn 0.4 O 2 (SC-NFM424) with a preferred orientation of the (003) facet by a simple resintering method, which delivered a high capacity of 172.3 mA h g –1 and stable cycling stability (80.0% after 450 cycles at 1 C). The various characterizations confirm that SC-NFM424 can effectively suppress the side reactions and structural degradation during the charge/discharge process. Moreover, the assembled 18650 cylindrical-type SC-NFM424||HC cell shows a capacity of 1726 mA h and an energy density of 172.2 W h kg –1 with a prominent cycling retention over 91.6% after 300 cycles at 0.5 C, which represents record values for high-energy and cycling stability of NIBs among the various cathode-based Ah-level cells.