Surface and Interfacial Chemistry in the Nickel‐Rich Cathode Materials

Abstract

With increasing demands for high energy lithium‐ion batteries, layered nickel‐rich cathode materials have been considered as the most promising candidate due to their high reversible capacity and low cost. Although some of the materials with nickel contents ≦60 % were commercialized, there are tremendous obstacles for further improvement of electrochemical performance, which is strongly related to the unstable cathode surface and interfacial properties. In this regard, a specific review on the interfacial chemistry between the cathode and electrolyte during electrochemical testing is provided. We highlight the underpinning interfacial chemistry and degradation mechanisms of the cathode materials. Finally, light is shed on the recent efforts for enhancing the interfacial stability of the nickel‐rich cathode materials.

Synthesis and Manipulation of Single-Crystalline Lithium Nickel Manganese Cobalt Oxide Cathodes: A Review of Growth Mechanism

“…Lithium nickel manganese cobalt oxide (NMC) cathodes have been critical pillars of advanced lithium ion batteries at current state (Chen et al, 2019;Xu et al, 2019;Zhou et al, 2019;Kim et al, 2020;Li et al, 2020;Wang et al, 2020b;Wu et al, 2020;Zhang, 2020;Zheng et al, 2020). The particle's crystallinity and morphology can put significant influences on the energy density, cycling stability, and rate capability of the NMC cathodes in practical applications (Liu et al, 2018;Fan et al, 2020).…”

Facile Dual-Protection Layer and Advanced Electrolyte Enhancing Performances of Cobalt-free/Nickel-rich Cathodes in Lithium-Ion Batteries

“…On the other hand, the fresh PP@NMT also shows not only improved cycling performance compared to the fresh bare NMT but also impressive results among the coating strategies for Ni-rich cathodes (Figure S8 and Table S1). The major issues of capacity decay during cycling can be classified as TM ion dissolution by the attack of HF (which is always present in LiPF 6 /carbonate-based electrolytes) and the cathode material structural degradation, resulting in phase transformation. , Also, the formed residual Li compounds on the surface of the exposed NMT tend to be decomposed in the presence of protons or other acidic species like HF and generate more water , that can promote HF formation in LiPF 6 -based electrolytes and trigger more TM dissolution during cycling. , According to the results, we consider the PP-coating layer could act as a dual-functional protection layer for the NMT cathode.…”

Enhanced Storage and Interface Structure Stability of NCM811 Cathodes for Lithium‐Ion Batteries by Hydrophobic Fluoroalkylsilanes Modification

“…[2,3] However, NCM cathode materials generally suffer from Li þ /Ni 2þ cation mixing, transition metal (TM) dissolution, stressinduced microcracks, and surface/interface structural degradation, thereby impeding its commercial application. [4][5][6][7] Another important issue is that the NCM cathode materials with high Ni content show extreme sensitivity to air and moisture during preparation and storage. [8][9][10][11] This high sensitivity can be mainly attributed to the fact that Ni 3þ tends to be reduced to Ni 2þ when exposed in air, along with loss of lattice Li on the surface of NCM cathode materials.…”