Boron-doped sodium layered oxide for reversible oxygen redox reaction in Na-ion battery cathodes

作者：Yu-Jie Guo, Pengfei Wang, Yubin Niu, Xu‐Dong Zhang, Qinghao Li, Xiqian Yu, Min Fan, Wan‐Ping Chen, Yang Yu, Xiangfeng Liu, Qinghai Meng, Sen Xin, Ya‐Xia Yin, Yu‐Guo Guo · 发表于：Nature Communications · 年份：2021 · DOI：10.1038/s41467-021-25610-7 · 被引用次数：416 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、Advanced battery technologies research

Abstract Na-ion cathode materials operating at high voltage with a stable cycling behavior are needed to develop future high-energy Na-ion cells. However, the irreversible oxygen redox reaction at the high-voltage region in sodium layered cathode materials generates structural instability and poor capacity retention upon cycling. Here, we report a doping strategy by incorporating light-weight boron into the cathode active material lattice to decrease the irreversible oxygen oxidation at high voltages (i.e., >4.0 V vs. Na + /Na). The presence of covalent B–O bonds and the negative charges of the oxygen atoms ensures a robust ligand framework for the NaLi 1/9 Ni 2/9 Fe 2/9 Mn 4/9 O 2 cathode material while mitigating the excessive oxidation of oxygen for charge compensation and avoiding irreversible structural changes during cell operation. The B-doped cathode material promotes reversible transition metal redox reaction enabling a room-temperature capacity of 160.5 mAh g −1 at 25 mA g −1 and capacity retention of 82.8% after 200 cycles at 250 mA g −1 . A 71.28 mAh single-coated lab-scale Na-ion pouch cell comprising a pre-sodiated hard carbon-based anode and B-doped cathode material is also reported as proof of concept.