The global shift towards low-carbon energy storage has increased interest in sodium-ion batteries(SIBs)as a safer,cost-effective alternative to lithium-ion batteries.However,the commercial viability has been limited b...The global shift towards low-carbon energy storage has increased interest in sodium-ion batteries(SIBs)as a safer,cost-effective alternative to lithium-ion batteries.However,the commercial viability has been limited by compatibility issues between high-energy-density cathode materials,such as Na_(3)V_(2)(PO_(4))_(2)F_(3)(NVPF),and high-voltage electrolytes.Addressing the challenges,H-NaODFB(comprising 93.91%NaODFB and 5.85%NaBF_(4))electrolyte significantly improves the electrochemical performance and stability of NVPF cathodes,Na/NVPF half-cells using H-NaODFB electrolyte retained 92.4%capacity after 900cycles,while Na/Na symmetric cells demonstrated a cycle life exceeding 600 h at 0.5 mA cm^(-2).The superior performance is attributed to improved Na^(+)(de)intercalation reversibility,lower interfacial impedance(619.8 vs.10,650.0Ω),and faster reaction kinetics compared to NaODFB alone.Advanced time of flight-secondary ion mass spectrometry(TOF-SIMS),X-ray photoelectron spectroscopy(XPS)and aberration corrected transmission electron microscope(AC-TEM),combined with first-principles calculations,revealed that NaBF_(4)in the H-NaODFB electrolyte plays a critical role in forming a stable cathode electrolyte interphase(CEI).The CEI consists of an initial inorganic and organic layer,followed by a fluoroborate layer,and finally a stable organic-inorganic polymeric layer,enhancing electrode stability and preventing over-oxidation.These findings provide valuable insights for designing high-performance electrolytes for SIBs.展开更多
基金financially supported by the Cultivation and Construction of Ten National Science and Technology Innovation Platforms in Qinghai Province(2024-ZJ-J03)Xining Major Science and Technology Innovation Platform Capacity Building Project(2024-Z1)+1 种基金funding from Young Scholars of Western China,Chinese Academy of Sciences(E110HX0501)Qinghai Province Youth Science and Technology Talent Support Project(2022QHSKXRCTJ06)。
文摘The global shift towards low-carbon energy storage has increased interest in sodium-ion batteries(SIBs)as a safer,cost-effective alternative to lithium-ion batteries.However,the commercial viability has been limited by compatibility issues between high-energy-density cathode materials,such as Na_(3)V_(2)(PO_(4))_(2)F_(3)(NVPF),and high-voltage electrolytes.Addressing the challenges,H-NaODFB(comprising 93.91%NaODFB and 5.85%NaBF_(4))electrolyte significantly improves the electrochemical performance and stability of NVPF cathodes,Na/NVPF half-cells using H-NaODFB electrolyte retained 92.4%capacity after 900cycles,while Na/Na symmetric cells demonstrated a cycle life exceeding 600 h at 0.5 mA cm^(-2).The superior performance is attributed to improved Na^(+)(de)intercalation reversibility,lower interfacial impedance(619.8 vs.10,650.0Ω),and faster reaction kinetics compared to NaODFB alone.Advanced time of flight-secondary ion mass spectrometry(TOF-SIMS),X-ray photoelectron spectroscopy(XPS)and aberration corrected transmission electron microscope(AC-TEM),combined with first-principles calculations,revealed that NaBF_(4)in the H-NaODFB electrolyte plays a critical role in forming a stable cathode electrolyte interphase(CEI).The CEI consists of an initial inorganic and organic layer,followed by a fluoroborate layer,and finally a stable organic-inorganic polymeric layer,enhancing electrode stability and preventing over-oxidation.These findings provide valuable insights for designing high-performance electrolytes for SIBs.
