Surface Modification on Nickel Rich Cathode Materials for Lithium‐Ion Cells: A Mini Review

Abstract

Nickel‐rich (Ni‐rich) layered oxides are considered as the most promising cathode candidates for lithium‐ion cells owing to their high theoretical specific capacity. However, the higher nickel content endows structural deformation through unwanted phase transitions and parasitic side reactions that lead to capacity fading upon prolonged cycling. Hence, a deep understanding of the chemistry and structural behaviour is essential for developing Ni‐rich Lithium Nickel Cobalt Manganese oxide (NCM) cathode‐based high‐energy batteries. The present review focuses on the different challenges associated with Ni‐rich NCM materials and surface modification as a strategy to solve the issues associated with NCM materials, assessment of several coating materials, and the recent developments in the surface modification of Ni‐rich NCMs, with an in‐depth discussion on the impact of coating on the degradation mechanism.

Lithium-Rich Li1.17Ni0.17Co0.17Mn0.5O2 Cathode Material for Lithium-Ion Cells: Effect of Calcination Temperature on Electrochemical Performance

“…The clear splitting of (006)/(012) and (018)/(110) peaks indicates the presence of the layered structures. 26,36,37 The specimen calcined at 900 °C showed a lower reflection intensity. However, a considerable increase in reflection intensity is seen for the samples calcined at 950 °C, which is caused by improved crystallization.…”

Degradation mechanisms and modification strategies of nickel-rich NCM cathode in lithium-ion batteries

“…These structural and chemical evolutions in Ni-rich cathode materials give rise to several underlying performance degradation mechanisms, including exacerbated Li/Ni cation disorder [17,18], oxygen evolution [19,20], layered-spinel-rocksalt phase transition [21][22][23], intergranular and intragranular microcracking [24][25][26], and transition metal dissolution [27] (as depicted in figure 2). Collectively, these mechanisms contribute to performance degradation and a shortened cycle life for Ni-rich NCM cathode materials [28][29][30][31]. The degradation pathways of Ni-rich NCM cathode materials, contributing to these challenges, are complex and interconnected.…”

A review of the degradation mechanisms of NCM cathodes and corresponding mitigation strategies

“…Many inorganic coatings can be implemented in amorphous and crystalline forms. For an extensive review of the coating materials, the reader can be referred to one of the most recent coating-focused reviews [19,[172][173][174].…”

“…Li3PO4 coating synthesis has been widely investigated due to the simple and beneficial fabrication route [153,174,184,185]. The most popular method is synthesizing the coating via a wet-chemical procedure by adding phosphoric acid.…”