Kosmotropic aqueous processing solution for green lithium battery cathode manufacturing

The global pursuit of carbon neutrality is driving efforts toward environmentally friendly aqueous electrode manufacturing. However, the inherent chemical reactivity of water with cathode materials remains a challenge to achieving this goal. Here, we design a class of aqueous processing solutions based on the kosmotropic effect. Ion hydration shells in the kosmotropic solutions are restructured to form an ordered state of anion–water clusters and to stabilize local hydration structure adjacent to cathode materials. Consequently, interfacial side reactions and structural degradation of Ni-rich cathode materials are mitigated. The kosmotropic solution-processed LiNi0.8Co0.1Mn0.1O2 cathode achieve high specific and areal capacities (≥ 205 mAh g–1 and ≥ 3.7 mAh cm–2) together with stable cyclability, which are comparable to those of commercial N-methyl-2-pyrrolidone (NMP)-processed cathodes. Techno-economic analysis demonstrates that this kosmotropic solution approach reduces energy consumption in battery manufacturing by 46% compared to the NMP-based process, highlighting its practical and sustainable viability. Current lithium-ion battery cathode production relies on toxic solvents, raising another environmental concern. Here, authors present a kosmotropic aqueous processing solution, enabling sustainable, cost-effective cathode production while preserving commercial electrochemical performance.