There is an urgent need for high-safety and high-energy lithium-ion batteries to satisfy the rapidly increasing need for energy storage. Nickel-rich layered cathodes have been at the forefront of the revolution for batteries due to their relatively high capacity and low cost. However, with the increase of nickel content, the batteries suffer from severe safety concerns, which caused by thermal runaway. Here we show that the ultraconformal cathode-electrolyte interphase (CEI) protective skin with high inorganic content dramatically enhances the safety of high-energy practical Li-ion pouch cells. We find that the robust CEI skin significantly improves the intrinsic thermal stability, mitigates the evolution of oxygen resulting from phase transition, and effectively suppresses the associated parasitic reactions between the delithiated cathodes and electrolyte. The in-situ CEI engineering strategy is simple and suitable for practical industrial manufacture, and it provides design ideas for aggressive nickel-rich cathodes towards safe and high-energy batteries.

迫切需要高安全性和高能量的锂离子电池来满足快速增长的储能需求。由于其相对较高的容量和较低的成本，富镍层状阴极一直处于电池革命的前沿。然而，随着镍含量的增加，电池因热失控而面临严重的安全问题。在这里，我们展示了具有高无机含量的超保形阴极 - 电解质界面 (CEI) 保护皮显着提高了高能实用锂离子软包电池的安全性。我们发现坚固的 CEI 表层显着提高了内在的热稳定性，减轻了由相变引起的氧气的释放，并有效抑制脱锂正极和电解质之间的相关寄生反应。原位 CEI 工程策略简单，适用于实际工业制造，它为安全和高能电池的侵略性富镍正极提供了设计思路。