Silicon(Si)is a promising high-capacity anode in lithium-ion batteries but suffers from chronic chemical degradation and capacity fading during calendar aging,greatly hindering its automobile applications.Electrolyte ...Silicon(Si)is a promising high-capacity anode in lithium-ion batteries but suffers from chronic chemical degradation and capacity fading during calendar aging,greatly hindering its automobile applications.Electrolyte engineering currently relies on conventional evaluation criteria of reducing coulombic consumption,which implicitly presume its equivalence to irreversible capacity loss and complicates battery development.We introduce the detrimental ratioρto quantify the fraction of parasitic species that permanently degrades active material.This metric is independent and crucially complements total coulombic consumption for accurate performance evaluation.We systematically investigate multiple electrolyte formulations using high-precision leakage current measurements,open-circuit-voltage experiments,and post-mortem characterizations.Although some electrolytes exhibit similarly low coulombic consumption,they diverge significantly in capacity retention andρ.Especially,dimethyl-carbonate-based localized-high concentration electrolyte can synergically achieve low coulombic consumption and detrimental ratioρduring calendar aging,owing to its chemically inert and structurally resilient solidelectrolyte interface with minimal isolated Si material.By contrast,increasing fluoroethylene carbonate(FEC)additive content suppresses electrolyte breakdown but suffers aggravated chemical degradation of more LixSi isolation for irreversible capacity loss with a risingρ.This study critically reveals that the chemistry-characteristic detrimental ratioρestablishes physically informed performance evaluation to pave the way for accelerating battery development.展开更多
基金supported by the U.S.Department of Energy(DOE),Office of Energy Efficiency and Renewable Energy(EERE),Vehicle Technologies Office(VTO)under the Silicon Consortium Seedling project received by Z.H.Coperated for the DOE Office of Science by UChicago Argonne,LLC,under Contract DE-AC02-06CH11357+2 种基金Pacific Northwest National Laboratory(PNNL)was supported by the U.S.DOE,Office of Advanced Research Projects Agency-Energy(ARPA-E)under the EVs4ALL Program with the contract number DE-AC05-76RL01830operated by Battelle for the DOE under Contract DE-AC0576RL01830performed at the Oak Ridge National Laboratory(GMV)and supported by U.S.DOE’s VTO under the Silicon Consortium Program received by G.M.V.and directed by Carine Steinway,Nicolas Eidson Thomas,Thomas Do。
文摘Silicon(Si)is a promising high-capacity anode in lithium-ion batteries but suffers from chronic chemical degradation and capacity fading during calendar aging,greatly hindering its automobile applications.Electrolyte engineering currently relies on conventional evaluation criteria of reducing coulombic consumption,which implicitly presume its equivalence to irreversible capacity loss and complicates battery development.We introduce the detrimental ratioρto quantify the fraction of parasitic species that permanently degrades active material.This metric is independent and crucially complements total coulombic consumption for accurate performance evaluation.We systematically investigate multiple electrolyte formulations using high-precision leakage current measurements,open-circuit-voltage experiments,and post-mortem characterizations.Although some electrolytes exhibit similarly low coulombic consumption,they diverge significantly in capacity retention andρ.Especially,dimethyl-carbonate-based localized-high concentration electrolyte can synergically achieve low coulombic consumption and detrimental ratioρduring calendar aging,owing to its chemically inert and structurally resilient solidelectrolyte interface with minimal isolated Si material.By contrast,increasing fluoroethylene carbonate(FEC)additive content suppresses electrolyte breakdown but suffers aggravated chemical degradation of more LixSi isolation for irreversible capacity loss with a risingρ.This study critically reveals that the chemistry-characteristic detrimental ratioρestablishes physically informed performance evaluation to pave the way for accelerating battery development.
