The Cycle Stability and Rate Performance of LiNi_0.8Mn_0.1Co_0.1O₂ Enhanced by Mg Doping and LiFePO₄ Coating

Abstract

Nickel‐rich layered oxide LiNi0.8Mn0.1Co0.1O2 became one of the preferred cathode materials for lithium‐ion batteries because of its advantages in capacity, cost and environmental protection. However, increased nickel content inevitably leads to more serious structural deterioration, such as irreversible phase transition, unexpected side effects as well as Li+/Ni2+ mixing, etc. This results in poor cycle stability and rate performance. Herein, we proposed a co‐modification strategy for Mg doping and LiFePO4 coating to enhance the aforementioned electrochemical performance of LiNi0.8Co0.1Mn0.1O2. The results indicated that Mg0.02‐NCM@20LFP exhibited lower surface film resistance and charge transfer resistance than pristine material after 200 cycles at 1C. A cycle retention rate of 90.8 % can still be maintained after 100 cycles at 0.2C. When returning to 0.1C after 5C high magnification, 98 % of the capacity can be recovered, showing that the material has good structural integrity.

Damage mechanisms and recent research advances in Ni‐rich layered cathode materials for lithium‐ion batteries

“…In their study, Zhang et al 130 . employed a dual approach involving magnesium ion doping and a coating of LiFePO 4 to enhance the cyclability and rate performance of nickel‐rich oxides (Figure 10A).…”

“…Reproduced with permission. 130 Copyright 2022, John Wiley and Sons. (B) Charge and discharge curves of the original and modified samples at 0.2C.…”

“…Reproduced with permission. 130 Copyright 2022, John Wiley and Sons. (D) Performance at 2.5-4.3 V and 0.2C rate for 100 cycles of original and modified samples.…”

High-Performance High-Nickel Multi-Element Cathode Materials for Lithium-Ion Batteries

“…To solve this issue, researchers have introduced lithium-containing compounds with high Li + conductivity for surface modification. These compounds include LiCoO 2 [184], LiNi 0.333 Co 0.333 Mn 0.333 O 2 [185], Li 2 ZrO 3 [186][187][188], LiZr 2 (PO 4 ) 3 [189], LiAlO 2 [190], Li 2 SiO 3 [191], Li 2 MnO 3 [192], LiNbO 3 [193,194], LiFePO 4 [195,196], Li 3 PO 4 [197][198][199], LiH 2 PO 4 [200], LiBO [201,202], and LLAO [203]. Yang et al [188] utilized the Couette-Taylor reaction to deposit a surfacecoated Li 2 ZrO 3 layer onto LiNi 0.90 Co 0.04 Mn 0.03 Al 0.03 O 2 (NCMA), with a thickness of approximately 2.5 nm.…”

“…Experimental results also showed that coating modification effectively improved the cycling stability of NCM811, increasing the capacity retention rate from 19% to 70% after 500 cycles. Zhang et al [196] introduced a modification strategy of Mg doping and LiFePO 4 coating on NCM811. The modified cathode displayed lower charge transfer resistance than the original material.…”