Effects of Coating on the Electrochemical Performance of a Nickel-Rich Cathode Active Material

Abstract

: Due to their safety and high power density, one of the most promising types of all-solid-state lithium batteries is the one made with the argyrodite solid electrolyte (ASE). Although substantial efforts have been made toward the commercialization of this battery, it is still challenged by some technical issues. One of these issues is to prevent the side reactions at the interface of the ASE and the cathode active material (CAM). A solution to address this issue is to coat the CAM particles with a material that is compatible with both ASE and CAM. Prior studies show that the lithium niobate, LiNbO3, (LNO) is a promising material for coating CAM particles to reduce the interfacial side reactions. However, no systematic study is available in the literature to show the effect of coating LNO on CAM performance. This paper aims to quantify the effect of LNO coating on the electrochemical performance of a nickel-rich CAM. The electrochemical performance parameters that are studied are the capacity, cycling performance, and rate performance of the coated-CAM; and the effectiveness of the coating to prevent the side reactions at the ASE and CAM interface is out of the scope of this study. To eliminate the effect of side reactions at the ASE and CAM interface, we conduct all tests in the organic liquid electrolyte (OLE) cells to solely present the effect of coating on the CAM performance. For this purpose, 0.5 wt% and 1 wt% LNO are used to coat the LiNi0.6Mn0.2Co0.2O2 (NMC-60) CAM through two synthesizing methods. Consequently, the effects of the synthesizing method and the coating weight percentage on the NMC-60 performance are presented.

The role of niobium in layered oxide cathodes for conventional lithium-ion and solid-state batteries

“…35,[53][54][55][56] Despite a plethora of compositional options for coatings, Nb-based ones represent a promising method to stabilize cathode/electrolyte interfaces. LiNbO 3 can be considered the quintessential Nb-based coating and can be prepared in multiple ways, including sol-gel, 42,53,[57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73] dry coating, 55,61,[74][75][76][77][78][79] and atomic layer deposition (ALD). 80,81 Sol-gel derived coatings require the least demand with regards to equipment, and the procedure is mature.…”

“…The optimal thickness can generally vary within the range of ∼2 to 10 nm. 42,56,58,60,62,65,67,68,[79][80][81][87][88][89] Nevertheless, only one of them quantifies the degree of uniformity or variation in thickness. This particular study employed atomic force microscopy (AFM) to measure particle roughness, which decreased with added coating, likely suggesting a reduction in initial porosity.…”

Review on New-Generation Batteries Technologies: Trends and Future Directions

“…In [68], the authors conduct an extensive review of advancements in the coating of NMC batteries, exploring multi-functionalities and mechanisms aimed at enhancing their electrochemical properties and overall performance. In [69], the authors discuss the potential of the argyrodite solid electrolyte (ASE) for use in all-solid-state lithium batteries. They propose lithium niobate (LiNbO 3 , LNO) as a coating material that is compatible with both ASE and cathode active materials (CAM).…”

Ionic Conductivity of the Li6PS5Cl0.5Br0.5 Argyrodite Electrolyte at Different Operating and Pelletizing Pressures and Temperatures

“…The understanding gained from this study can guide further optimization efforts and contribute to the development of safe, high-performance solid-state batteries for various applications. The authors also refer the readers to references [36][37][38][39][40] for further information on argyrodite electrolytes and solid-state lithium batteries.…”