高镍正极材料LiNi0.83Co0.12Mn0.05O2双包覆改性及软包锂离子电池应用研究

Dual-Coating of LiNi0.83Co0.12Mn0.05O2 with Nanosized ZrO2 and B2O3 for Lithium-Ion Pouch Cell Application

摘要:

对电极材料进行包覆改性，是提升锂离子电池能量密度、循环寿命和安全性等重要特性的有效策略。基于高镍三元正极材料Ni_0.83Co_0.12Mn_0.05O₂（Ni83），通过纳米ZrO₂和纳米B₂O₃双组分包覆，制备得到了ZB-Ni83材料，并对其材料特性和软包锂离子电池性能进行了研究。ICP-OES元素分析结果表明，ZrO₂和B₂O₃已成功实现包覆，ZB-Ni83材料中锆含量为0.166 4%，硼含量为0.068 9%。XRD和SEM结果表明，ZB-Ni83材料为具有层状结构和良好结晶度的紧密实心二次球形颗粒，该结构有利于提高材料的振实密度及电解液浸润性。采用ZB-Ni83正极材料的软包锂离子电池具有良好的倍率、循环和安全性能。在2 C条件下，ZB-Ni83电芯的比容量为182 mA?h?g^–1、容量保持率为92.6%；在45 ℃高温循环及截止容量保持率85%条件下，ZB-Ni83电芯的循环次数约为1100次，而原始Ni83电芯的循环次数仅为约600次。对ZB-Ni83电芯进行满电130 ℃的热箱实验，结果未发生破裂、冒烟、爆炸、着火等现象。本研究为高镍材料的创新和改进提供了实验参考和可行思路。

Abstract:

Coating modification is an effective strategy to improve the important characteristics of lithium-ion batteries such as energy density， cycle life and safety. Herein， nano-zirconia （ZrO₂） and boron oxide （B₂O₃） were simultaneously used to coat the high-nickel ternary cathode material Ni_0.83Co_0.12Mn_0.05O₂ （Ni83） to obtain ZB-Ni83， and its materials characteristics and pouch lithium-ion cell performance were studied. The ICP-OES elemental analysis showed ZrO₂ and B₂O₃ have been successfully coated and the ZB-Ni83 contained 0.166 4% of zirconium and 0.068 9% of boron. XRD and SEM characterizations showed that the ZB-Ni83 were compact solid secondary spherical powder particles with a layered structure and high crystallinity， which is beneficial to improve the tap density and electrolyte wettability of the material. The lithium-ion pouch cell with the dual-coated Ni83 exhibited high rate， cycling and safety performances： the specific capacity of ZB-Ni83 cell at 2 C was 182 mA·h g^-1， and the capacity retention rate was 92.6%； the ZB-Ni83 cell showed around 1100 cycles under high temperature cycle at 45 °C and capacity retention of 85%， while the original Ni83 cell showed approximately 600 cycles； the ZB-Ni83 cell has passed the hot box test at 130 °C for 30 min， showing no rupture， smoking， explosion， or fire. This research provides an experimental reference and a feasible idea for the innovation and improvement of high-nickel materials.