biostudies-literatureWang HNatural Science Foundation of Fujian ProvinceNational Natural Science Foundation of ChinaNatural Science Foundation of Fujian Province (Fujian Provincial Natural Science Foundation)National Natural Science Foundation of China (National Science Foundation of China)1034-1042https://www.ebi.ac.uk/biostudies/studies/S-EPMC12373503biostudies-literatureUnknown20(8)Unwanted side reactions occurring at electrode|electrolyte interfaces significantly impact the cycling life of lithium metal batteries. However, a comprehensive view that rationalizes these interfacial reactions and assesses them both qualitatively and quantitatively is not yet established. Here, by combining multiple analytical techniques, we systematically investigate the interfacial reactions in lithium metal batteries containing ether-based non-aqueous electrolyte solutions. We quantitatively monitor various nanoscale-driven processes such as the reduction and oxidation pathways of lithium salt and organic solvents, the formation of various solid-electrolyte interphase species, the gas generation within the cell and the cross-talk processes between the electrodes. We demonstrate that the consumption of lithium ions owing to the continuous decomposition of the lithium bis(fluorosulfonyl)imide salt, which dominates the interfacial reactions, results in ion depletion during the cell discharge and battery failure. On the basis of these findings, we propose an electrolyte formulation in which lithium bis(fluorosulfonyl)imide content is maximized without compromising dynamic viscosity and bulk ionic conductivity, aiming for long-cycling battery performance. Following this strategy, we assemble and test Li (20 μm thickness)||LiNi_0.8Mn_0.1Co_0.₁O₂ (17.1 mg cm^-² of active material) single-layer stack pouch cells in lean electrolyte conditions (that is, 2.1 g Ah^-1), which can effectively sustain 483 charge (0.2 C or 28 mA)/discharge (1 C or 140 mA) cycles at 25 °C demonstrating a discharge capacity retention of about 77%.Nature nanotechnologyApplication-driven design of non-aqueous electrolyte solutions through quantification of interfacial reactions in lithium metal batteries.PMC12373503No. 2024J010048No. 51962010No. 22209085Li HWan PLiu NFeng FChen FWu EWang HYan XZhang RUlissi UOuyang CHuang SXu BLiang JGe XYe GLuo XYe FLiu CWang YSun JHung STZhou JfalseApplication-driven design of non-aqueous electrolyte solutions through quantification of interfacial reactions in lithium metal batteries.Unwanted side reactions occurring at electrode|electrolyte interfaces significantly impact the cycling life of lithium metal batteries. However, a comprehensive view that rationalizes these interfacial reactions and assesses them both qualitatively and quantitatively is not yet established. Here, by combining multiple analytical techniques, we systematically investigate the interfacial reactions in lithium metal batteries containing ether-based non-aqueous electrolyte solutions. We quantitatively monitor various nanoscale-driven processes such as the reduction and oxidation pathways of lithium salt and organic solvents, the formation of various solid-electrolyte interphase species, the gas generation within the cell and the cross-talk processes between the electrodes. We demonstrate that the consumption of lithium ions owing to the continuous decomposition of the lithium bis(fluorosulfonyl)imide salt, which dominates the interfacial reactions, results in ion depletion during the cell discharge and battery failure. On the basis of these findings, we propose an electrolyte formulation in which lithium bis(fluorosulfonyl)imide content is maximized without compromising dynamic viscosity and bulk ionic conductivity, aiming for long-cycling battery performance. Following this strategy, we assemble and test Li (20 μm thickness)||LiNi_0.8Mn_0.1Co_0.₁O₂ (17.1 mg cm^-² of active material) single-layer stack pouch cells in lean electrolyte conditions (that is, 2.1 g Ah^-1), which can effectively sustain 483 charge (0.2 C or 28 mA)/discharge (1 C or 140 mA) cycles at 25 °C demonstrating a discharge capacity retention of about 77%.2025-01-01T00:00:00Z2025 Aug2026-05-09T10:46:28.631Z2026-04-08T00:48:48.421ZS-EPMC123735034043720010.1038/s41565-025-01935-y