Wang Jingqiang, Chen Diancheng, Dong Hanghang, Sun Qing-Qun, Li Meng-Ying, Zhang Guang-Yu, Hu Hai-Yan, Pian Yijing, Yu Jing, Zhu Yan-Fang, Wei Hang, Sun Yang, Zhao Shiqiang, Chu Haibin, Liu Jian, Xiao Yao
College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot, Inner Mongolia 010021, China.
School of Materials, Sun Yat-sen University, Shenzhen 518107, China.
ACS Nano. 2025 Sep 9;19(35):31901-31914. doi: 10.1021/acsnano.5c11703. Epub 2025 Aug 27.
Mn-based oxide cathodes for sodium-ion batteries (SIBs) often suffer from structural degradation caused by Jahn-Teller distortion and irreversible phase transitions. Here, we propose a dual-site stabilization strategy by Mo/Mg codoping, which not only drives the transformation of the tunnel-type NaMnO into a P2-layered structure (NaMnMoMgO, denoted as MoMg-12) by modulating the total energy to enhance capacity but also employs Mo and Mg ions substituting Mn sites to implement synergistic dual-pinning engineering to stabilize the structure. This dual-pinning mechanism concurrently suppresses Jahn-Teller distortion by stabilizing Mn redox activity and improves air stability by reducing Na/H exchange while promoting a hydrophobic surface. The optimized MoMg-12 cathode delivers a high specific capacity of 189 mAh g within its stable P2-type layered structure coupled with superior rate capability and long-term cycling stability. In addition, its practical viability is demonstrated when paired with a NaCO sodium compensation additive. This study highlights the effectiveness of the dual-pinning engineering in preserving structural integrity and offers a practical design example for high-energy-density and air-stable SIB cathodes.
用于钠离子电池（SIB）的锰基氧化物阴极常常因 Jahn-Teller 畸变和不可逆相变而遭受结构退化。在此，我们提出一种通过 Mo/Mg 共掺杂的双位点稳定策略，该策略不仅通过调节总能量驱动隧道型 NaMnO 转变为 P2 层状结构（NaMnMoMgO，记为 MoMg-12）以提高容量，还利用 Mo 和 Mg 离子取代 Mn 位点来实施协同双钉扎工程以稳定结构。这种双钉扎机制通过稳定 Mn 氧化还原活性同时抑制 Jahn-Teller 畸变，并通过减少 Na/H 交换同时促进疏水表面来提高空气稳定性。优化后的 MoMg-12 阴极在其稳定的 P2 型层状结构内具有 189 mAh g 的高比容量，同时具备优异的倍率性能和长期循环稳定性。此外，当与 NaCO 钠补偿添加剂配对时，展示了其实际可行性。本研究突出了双钉扎工程在保持结构完整性方面的有效性，并为高能量密度和空气稳定的 SIB 阴极提供了一个实际设计示例。
