Among the current battery technologies, lithium-ion batteries (LIBs) are essential in shaping future energy landscapes in stationary storage and e-mobility. Among all components, choosing active cathode material (CAM) limits a cell’s available energy density (Wh kg⁻¹), and the CAM selection becomes critical. Layered Lithium transition metal oxides, primarily, LiNi_xMn_yCo_zO₂ (NMC) (x + y + z = 1), represent a prominent class of cathode materials for LIBs due to their high energy density and capacity. The battery performance metrics of NMC cathodes vary according to the different ratios of transition metals in the CAM. The non-electrode factors and their effect on the cathode performance of a lithium-ion battery are as significant in a commercial sense. These factors can affect the capacity, cycle lifetime, thermal safety, and rate performance of the NMC battery. Additionally, polycrystalline NMC comprises secondary clusters of primary crystalline particles prone to pulverization along the grain boundaries, which leads to microcrack formation and unwanted side reactions with the electrolyte. Single-crystal NMC (SC-NMC) morphology tackles the cycling stability issue for improved performance but falls short in enhancing capacity and rate capability. The compatibility of different combinations of electrolytes and additives for SC-NMC is discussed, considering the commercial aspects of NMC in electric vehicles. The review has targeted the recent development of non-aqueous electrolyte systems with various additives and aqueous and non-aqueous binders for NMC-based LIBs to stress their importance in the battery chemistry of NMC.

Redox shuttle additives are already known in the battery field to provide overcharge protection, mainly at high-voltage cathode electrodes. The electroactive species can get either oxidized at the cathode side or reduced at the anode side, preferentially during the battery cycling. The mechanism involves the generation of positively charged radicals during oxidation and the subsequent diffusion and reduction at the anode surface. This shuttling process continues between the electrodes through baseline electrolytes. Redox shuttle additives are extensively studied in Li-ion batteries (LIBs).^1–3 Benzophenone (BP) is one of the redox shuttle additives used successfully in lithium-ion batteries.⁴ No report exists in the literature for BP additives in sodium-ion batteries (SIBs). This work investigates BP (an already known overcharge protecting additive) and substituted 4-methyl BP (4-methyl benzophenone) as an electrolyte additive in baseline electrolyte containing NaClO₄ in EC/PC solvent on both electrodes. The aim is to investigate BP's SEI-forming properties in sodium-ion batteries. The initial half-cell test with a Hard Carbon anode without and with 0.5 wt% 4-methyl BP as the additive is shown in Fig.1. 4-Methyl BP additive shows a large increase in specific capacity from 337 mAh gm^-1 to 438 mAh gm^-1 at 0.1C rate in a 5 mV - 1.5 V voltage range. The oral presentation will focus on the effect of additive concentration on the battery performance of HC and polyanionic cathode NVP in half-cell and full-cell configurations in Na-ion batteries. References: C. Buhrmester, L. Moshurchak, R. L. Wang, and J. R. Dahn, J. Electrochem. Soc., 153, A288 (2006). L. M. Moshurchak et al., J. Electrochem. Soc., 156, A309 (2009). M. Tang and J. Newman, J. Electrochem. Soc., 158, A530–A536 (2011). Q. Wang, S. M. Zakeeruddin, I. Exnar, and M. Grätzel, Electrochem. commun., 10, 651–654 (2008). Figure 1