Li Mingzhu, Li Qingping, Hu Maofeng, Du Yongxu, Duan Zhipeng, Fan Hongguang, Cui Yongpeng, Liu Shuang, Jin Yongcheng, Liu Wei
School of Materials Science and Engineering, Ocean University of China, Qingdao 266100, P. R. China.
School of Materials Science and Engineering, China University of Petroleum, Qingdao 266580, P. R. China.
Phys Chem Chem Phys. 2022 May 25;24(20):12214-12225. doi: 10.1039/d2cp00835a.
Spinel LiNiMnO (LNMO) is one potential cathode candidate for next-generation high energy-density lithium-ion batteries (LIBs). However, serious capacity decay from its poor structural stability, especially at high operating temperatures, shadows its application prospects. In this work, N-doped LNMO (LNMON) was synthesized by a facile co-precipitation method and multistep calcination, exhibiting a unique yolk-shell architecture. Concurrently, N dopants are introduced into a LNMO lattice, endowing LNMON with a more stable structure stronger Ni-N/Mn-N bindings. Benefiting from the synergistic effect of the yolk-shell structure and N-doped engineering, the obtained LNMON cathode exhibits an impressive rate and the state-of-the-art cycling capability, delivering a high capacity of 103 mA h g at 25 °C after 8000 cycles. Even at a high operating temperature of 60 °C, the capacity retention remains at 92% after 1000 cycles. The discovery of N dopants in improving the cycling capability of LNMO in our case offers a prospective approach to enable 5 V LNMO cathode materials with excellent cycling capability.
尖晶石LiNiMnO（LNMO）是下一代高能量密度锂离子电池（LIBs）的一种潜在正极候选材料。然而，由于其结构稳定性差，尤其是在高工作温度下，导致严重的容量衰减，这影响了其应用前景。在这项工作中，通过简便的共沉淀法和多步煅烧合成了N掺杂的LNMO（LNMON），其呈现出独特的蛋黄壳结构。同时，N掺杂剂被引入到LNMO晶格中，赋予LNMON更稳定的结构和更强的Ni-N/Mn-N键。受益于蛋黄壳结构和N掺杂工程的协同效应，所制备的LNMON正极表现出令人印象深刻的倍率性能和一流的循环性能，在8000次循环后，于25℃下仍具有103 mA h g的高容量。即使在60℃的高工作温度下，经过1000次循环后容量保持率仍为92%。在我们的研究中，N掺杂剂在提高LNMO循环性能方面的发现为实现具有优异循环性能的5V LNMO正极材料提供了一种前瞻性方法。
