Adaptive Solvation Evolution by Molecular Design Enables High-Performance Wide-Temperature Lithium-Ion Batteries.

The solvation structure is a decisive factor for the performance of lithium-ion batteries (LIBs) under extreme environments, and its evolution with temperature changes is particularly elusive. This work reports a strategy to regulate the coordination interactions between solvents, Li+, and anions through a local steric shielding effect of α-methyl-substituted solvents, thereby forming a temperature-adaptive evolution of the solvation structure, ensuring efficient ion transport over the entire temperature range (from -80°C to 100°C). Practical pouch cells demonstrated outstanding performance: 1 Ah LiFePO4 (LFP)||graphite (Gr) commercial pouch cells retained 87.4% capacity after 2000 cycles at 2 C and 25°C, and delivered stable discharge capacities down to -60°C (0.47 Ah). Meanwhile, the 1 Ah LiNi0.8Mn0.1Co0.1O2 (NMC811)||Gr pouch cells maintained 83.2% capacity over 4000 cycles at 1 C and 25°C, while also delivering 0.49 Ah at -80°C and maintaining operational functionality even at 100°C. The strategy offers a practical route toward LIB electrolytes with broad temperature adaptability and long cycle life.