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The loading levels of electrodes are one of the crucial parameters of high energy lithium-ion batteries (LIBs); however, their effects on specific energy and energy density remain insufficiently studied. Moreover, the rate capability can differ greatly with varying loading levels and hence requires further investigation. Herein, we investigated the relationship between electrode loading levels and electrochemical performance of LIBs via galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS). We found that the differences in performance stem from differing internal resistances at varying loading levels. On one hand, internal resistance decreased with a higher number of parallel connection; on the other hand, it increased with extension of electrical pathways. As a result, the optimal loading level of commercial LiNi0.6Co0.2Mn0.2O2 cathode materials was approximately 20 mg/cm2, which corresponds to an areal capacity of 3.3 mAh/cm2. These findings will assist in the further optimization of commercially available LIBs.

Abstract The increasing adoption of Ni‐rich cathode active materials in commercial liquid electrolyte Lithium‐ion batteries (LIBs) is testament to the improvements in the cathode stability through various surface modification strategies. The development of a deeper understanding of the cathode/electrolyte interface in LIBs has resulted in coatings capable of mitigating both surface and bulk cathode degradation mechanisms. However, due to increasing demands for safe and high energy density cells, a large portion of the research has now shifted towards applying Ni‐rich cathode active materials in inherently safer all‐solid‐state Lithium‐ion batteries (ASSLBs), with the resulting cathode surface modification strategies evolving differently. In this regard, a review outlining the surface modification strategies of Ni‐rich cathode materials applied in both LIB and ASSLB systems is provided. Within, a review of the traditional, advanced and specialized surface modification strategies of each system is discussed, along with a final perspective on the likely future direction of research regarding the design of system‐specific Ni‐rich cathode‐based surface modification strategies.