Enhancing microstructural and electrochemical stabilities of Ni-rich layered oxides is critical for improving the safety and cycle-life of high-energy Li-ion batteries. Here we propose a thermochemical cyclization strategy where heating polyacrylonitrile with LiNi_0.8Co_0.1Mn_0.1O₂ can simultaneously construct a cyclized polyacrylonitrile outer layer and a rock-salt bridge-like inner layer, forming a compact dual-coating of LiNi_0.8Co_0.1Mn_0.1O₂. Systematic studies demonstrate that the mild cyclization reaction between polyacrylonitrile and LiNi_0.8Co_0.1Mn_0.1O₂ induces a desirable “layered to rock-salt” structural transformation to create a nano-intermedium that acts as the bridge for binding cyclized polyacrylonitrile to layered LiNi_0.8Co_0.1Mn_0.1O₂. Because of the improvement of the structural and electrochemical stability and electrical properties, this cathode design remarkably enhances the cycling performance and rate capability of LiNi_0.8Co_0.1Mn_0.1O₂, showing a high reversible capacity of 183 mAh g^–1 and a high capacity retention of 83% after 300 cycles at 1 C rate. Notably, this facile and scalable surface engineering makes Ni-rich cathodes potentially viable for commercialization in high-energy Li-ion batteries.

中文翻译：

---

热化学环化构建高能锂离子电池用富镍层状氧化物阴极的桥接双涂层

提高富镍层状氧化物的微观结构和电化学稳定性对于提高高能锂离子电池的安全性和循环寿命至关重要。在这里，我们提出了一种热化学环化策略，其中加热聚丙烯腈与 LiNi _0.8 Co _0.1 Mn _0.1 O ₂可以同时构建环化聚丙烯腈外层和岩盐桥状内层，形成致密的双涂层 LiNi _0.8 Co _0.1 Mn _0.1 O ₂。系统研究表明，聚丙烯腈与LiNi _0.8 Co _0.1 Mn _0.1 O发生了温和的环化反应。_图2诱导了理想的“层状到岩盐”结构转变，以产生充当将环化聚丙烯腈结合到层状LiNi _0.8 Co _0.1 Mn _0.1 O ₂的桥梁的纳米中间体。由于结构和电化学稳定性以及电学性能的改善，这种正极设计显着提高了 LiNi _0.8 Co _0.1 Mn _0.1 O ₂的循环性能和倍率性能，显示出 183 mAh g ^{-1的高可逆容量}在 1 C 倍率下循环 300 次后容量保持率高达 83%。值得注意的是，这种简便且可扩展的表面工程使富镍正极有可能在高能锂离子电池中实现商业化。