ZrO2/B2O3双包覆单晶高镍材料及锂电池性能研究

Dual Coating of ZrO2 and B2O3 on Single-Crystal High Nickel Ternary Material and the Lithium-Ion Battery Performance

摘要:

开发高能量密度、低成本、高安全性和可持续的材料体系，对于锂电池的高质量发展具有重要意义。高镍三元正极材料具有质量能量密度高、倍率性能好、钴含量较低的优点，是长续航动力锂电池的首选，但其存在压实密度低、表面残碱高、高温循环易产气的问题。本文通过采用在不同温度下进行梯次包覆的方法，制备出ZrO₂/B₂O₃双组分包覆的单晶高镍材料（ZrO₂/B₂O₃@SCHN）。同时，对ZrO₂/B₂O₃双包覆单晶高镍材料及其锂电池性能进行了研究。研究结果表明：ZrO₂/B₂O₃@SCHN材料单一颗粒形貌明显，具有良好的层状晶体结构；ZrO₂/B₂O₃@SCHN锂离子软包电芯在45 ℃循环1500次后容量保持率高达85%，此外ZrO₂/B₂O₃@SCHN电芯通过热箱测试（130 ℃，30 min）后未发生破裂、冒烟、着火和爆炸等现象，表现出优异的热安全性。该研究为进一步改善单晶高镍材料的性能提供可靠的实验探索，为高能量密度长循环锂离子电池的研发提供参考。

Abstract:

Conventional high nickel materials are renowned for their high energy capacity and excellent rate performances. However， there remains some challenges for this materials， such as low compacted density， high residual alkali on the surface， and excessive gas generation during higher-temperature cycling due to side reactions. Herein， zirconium oxide and boron oxide were dually coated on single-crystal high-nickel （ZrO₂/B₂O₃@SCHN） material in this study. The experimental results showed that the ZrO₂/B₂O₃@SCHN presented a single-granularity and layered crystal structure. The dual-coated material exhibited around 1500 cycles with capacity retention of 85% at 45 ℃. In addition， the dual-coated material showed excellent thermal safety by passing the hot box experiment （130 ℃、30 min）， without rupture， smoke， fire or explosion. Thus， this study suggests a feasible approach for the advancement of single-crystal high nickel materials and provides solid experimental evidences for the research and development of high-energy-density and long-life lithium-ion batteries.