Role of Mn Content on the Electrochemical Properties of Nickel-Rich Layered LiNi_0.8–xCo_0.1Mn_0.1+xO₂ (0.0 ≤ x ≤ 0.08) Cathodes for Lithium-Ion Batteries

Abstract

Ni-rich layered oxides (Ni content >60%) are promising cathode candidates for Li-ion batteries because of their high discharge capacity, high energy density, and low cost. However, fast capacity fading, poor thermal stability, and sensitivity to the ambient moisture still plague their mass application. In this work, we systematically investigate the effects of Mn content on the structure, morphology, electrochemical performance, and thermal stability of the Ni-rich cathode materials LiNi(0.8-x)Co(0.1)Mn(0.1+x)O2 (0.0 ≤ x ≤ 0.08). It is demonstrated that with the increase in Mn content and decrease in Ni content, the cycling stability of LiNi(0.8-x)Co(0.1)Mn(0.1+x)O2 to a cutoff charge voltage of 4.5 V is significantly improved. The high-Mn-content electrode LiNi(0.72)Co(0.10)Mn(0.18)O2 shows a capacity retention of 85.7% after 100 cycles at a 0.2 C rate at room temperature, much higher than those of the lower Mn-content samples LiNi(0.80)Co(0.10)Mn(0.10)O2 (64.0%) and LiNi(0.76)Co(0.10)Mn(0.14)O2 (72.9%). The improved capacity retention of the high-Mn-content electrode LiNi(0.72)Co(0.10)Mn(0.18)O2 is due to the stabilization of the electrode/electrolyte interface, as evidenced by the lower solid-electrolyte interphase (SEI) resistance and charge-transfer resistance. Furthermore, with the increase in Mn content and decrease in Ni content, the thermal stability of the Ni-rich cathode is also remarkably enhanced.

Multishelled Ni‐Rich Li(NixCoyMnz)O2 Hollow Fibers with Low Cation Mixing as High‐Performance Cathode Materials for Li‐Ion Batteries

“…After 300 electrochemical cycles, the capacity retention was 84.36% for x = 0.8. This performance level is far superior to most Ni‐rich electrodes reported (Figure 4e) 1, 2, 25. Even when the Li/Li(Ni x Co y Mn z )O 2 cells were tested at a high cut‐off potential of 4.6 V versus Li/Li + for 100 cycles (Figure S9, Supporting Information), the capacity retention for the electrode with x = 0.5 was still 91.40%, much higher than the best previously reported value of 85% 12.…”

Ni and Co Segregations on Selective Surface Facets and Rational Design of Layered Lithium Transition‐Metal Oxide Cathodes

“…Previous investigation indicates that all TM have their advantages and drawbacks. [41][42][43] For example, Ni and Co are effi cient redox centers enabling Li-ion intercalation and deintercalation but their high mobility degrades material's cycle stability. Mn 4+ has high chemical stability which can stabilize the layered structure, but it has poor redox behavior because once Mn 4+ is reduced to Mn 3+ and Mn 2+ , the layered lattice structure is no longer stable and lattice reconstruction occurs due to the well-known Jahn-Teller effect [ 44,45 ] and increased cation mobility.…”

Elucidation of the surface characteristics and electrochemistry of high-performance LiNiO2

“…[3][4][5][6] A combination of different transition metals (e.g., LiNi x Mn y Co z O 2 or NMCs) further increases the complexity of the problem since phase separation and side reactions with electrolyte have been reported for different compositions. 7,8 Herein, we report a comprehensive study on the effect of various solid-state synthesis parameters on the crystal structures, morphologies, and surface characteristics of layered lithium nickel oxides and correlate these characteristics with electrochemical performance. The best LiNiO 2 demonstrated excellent electrochemical performance including high discharge capacity, good rate capability, and capacity retention.…”