Xue Ke, Yang Shenglong, Lai Feiyan, Zhang Xiaohui, Xie Yishun, Yang Guangchang, Pan Kai, Li Qingyu, Wang Hongqiang
Guangxi Key Laboratory of Low-Carbon Energy Materials, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, China.
College of Materials and Chemical Engineering, Guangxi Key Laboratory of Calcium Carbonate Resources Comprehensive Utilization, Hezhou University, Hezhou 542899, China.
ACS Appl Mater Interfaces. 2025 Jan 8;17(1):1286-1294. doi: 10.1021/acsami.4c17755. Epub 2024 Dec 18.
O3-type layered oxides are considered promising cathode materials for next-generation high-energy-density sodium-ion batteries (SIBs). However, they face challenges, such as low rate capacity and poor cycling stability, which arise from structural deformation, sluggish Na diffusion kinetics, and interfacial side reactions. Herein, a synergistic substitution strategy for transitional and interstitial sites was adopted to improve the structure stability and Na diffusion kinetics of the O3-type NaNiFeMnO. Simulation results indicate that Co/B codoping effectively lowers the Na migration energy barrier. In addition, the synergistic effect of Co/B codoping provides ultralow lattice strain during repeated Na deintercalation/intercalation. In situ characterization verified that the complex phase transformation during charge and discharge was suppressed, thereby significantly improving the structural stability. At 1 and 3 C, the capacity retention of the modified O3-Na(NiFeMn)CoBO (NFMCB) improved from 29.6% and 1.7% to 86.7% and 88.6% after 200 cycles, respectively. Even at 10 C, it could still produce 107.2 mAh·g. Furthermore, full cells assembled with this material and commercial hard carbon exhibit a high energy density of 316.2 Wh·kg and a capacity retention of 80.8% after 200 cycles at 1 C. It is expected that this strategy will facilitate the commercialization of O3-type layered oxides.
O3型层状氧化物被认为是下一代高能量密度钠离子电池（SIBs）很有前景的正极材料。然而，它们面临着诸如倍率性能低和循环稳定性差等挑战，这些挑战源于结构变形、缓慢的钠扩散动力学以及界面副反应。在此，采用了一种过渡和间隙位点的协同取代策略来提高O3型NaNiFeMnO的结构稳定性和钠扩散动力学。模拟结果表明，Co/B共掺杂有效地降低了钠迁移能垒。此外，Co/B共掺杂的协同效应在反复的钠脱嵌/嵌锂过程中提供了超低的晶格应变。原位表征证实，充放电过程中的复杂相变得到了抑制，从而显著提高了结构稳定性。在1 C和3 C下，改性后的O3-Na(NiFeMn)CoBO（NFMCB）在200次循环后的容量保持率分别从29.6%和1.7%提高到了86.7%和88.6%。即使在10 C下，它仍能产生107.2 mAh·g的容量。此外，用这种材料和商业硬碳组装的全电池在1 C下200次循环后表现出316.2 Wh·kg的高能量密度和80.8%的容量保持率。预计该策略将推动O3型层状氧化物的商业化。
