Amphiphilic surfactant-assisted cathode-electrolyte interphases for prolonged cycling performance in Ni-rich NCMA cathode materials of lithium-ion batteries

The nickel-rich LiNixCoyMnzAl1-x-y-zO2 (x + y + z = 1, NCMA) layered cathode has recently attracted attention as a promising cathode material; however, its lifespan is shortened upon cycling due to its poor interfacial stability. Our attempts to prolong its lifespan included modifying the surface of the NCMA cathode using an amphipathic coating precursor, 3-(N,N-dimethylpalmitylammonio) propanesulfonate (PAPS). Favorable chemical interactions between the hydrophilic PAPS precursor and hydrophilic surface of the NCMA cathode allow the sulfonate functional groups of the precursor to attach to the NCMA cathode surface. The subsequent heating process results in the formation of uniformly distributed cathode-electrolyte interphase (CEI) layers, which effectively suppress electrolyte decomposition. Consequently, the capacity retention of the PAPS-modified NCMA cathode improves at both room temperature (92.7%) and elevated temperatures (86.4%) compared with that of the pristine NCMA cathode (58.5% and 28.8%, respectively). Additional systematic analyses indicate that the PAPS-derived CEI layers improve the interfacial stability of the NCMA cathodes.