Near‐Room‐Temperature Quasi‐Solid‐State F‐Ion Batteries with High Conversion Reversibility Based on Layered Structured Electrolyte

Abstract

commercial Li-ion batteries (LIBs) have the shortcomings of energy density, safety, and cost, which derive from the single electron transfer of intercalation cathodes, the implementation of flammable liquid electrolyte and the usage of precious metals (e.g., cobalt), respectively. [4] These situations have prompted people to develop more advanced battery systems with different electrochemical mechanisms. Among, conversion-type Li metal batteries (e.g., Li-sulfur/fluoride batteries), [5,6] multivalent cation batteries (e.g., Mg/Zn batteries), [7] and emerging halide anion batteries (e.g., Cl/F-ion batteries) [8,9] are stepping into the stage center of advanced battery technology research. Despite that Li metal batteries exhibit the superior energy density advantage, the safety concerns involving Li anode dendrites and flammable organic electrolytes

Solvent-in-Salt Electrolytes for Fluoride Ion Batteries

“…Furthermore, the use of conversion electrodes based on transition metal fluorides can provide theoretical energy densities of up to 1393 Wh L –1 (588 Wh kg –1 ) enabled by the multielectron conversion and the high theoretical capacity of the transition metals . These merits, however, have not yet been fully realized for reversible and high energy density FIBs at room temperature (RT), with most of the previously reported FIBs using solid-state electrolytes at operating temperatures above 80 °C, ,, and more recently at 60 °C, despite many efforts to discover and study RT fluoride conductive materials. − …”

Accelerated Exploration of Fast Fluoride-Ion Conductors Based on Compositional Descriptors

“…Ba 0.175 Sn 0.775 La 0.05 F 2.05 exhibits a wide electrochemical window over 3.43 V, specifically from −0.43 to 3 V vs Pb/PbF 2 . This potential window is comparable to those of conventional Sn-containing solid electrolytes; KSn 2 F 5 exhibits a potential window from −0.45 to 3.98 vs Sn/SnF 2 ( E Sn/SnF 2 = −0.07 V vs E Pb/PbF 2 ) and PbSnF 4 is electrochemically stable from 0.5 to 1.5 V vs Pb/PbF 2 . , Given the combination of the wide potential window and high conductivity, Ba 0.175 Sn 0.775 La 0.05 F 2.05 is regarded as a promising candidate for use as a solid electrolyte compatible against positive electrodes, e.g., Bi/BiF 3 and Cu/CuF 2 ( E = 0.32 and 0.64 V vs Pb/PbF 2 ) …”

Construction and Interfacial Modification of a β-PbSnF4 Electrolyte with High Intrinsic Ionic Conductivity for a Room-Temperature Fluoride-Ion Battery

“…Therefore, the effect of interfacial decoration is obvious. Figure d shows a strong linear relationship between the logarithm of ionic conductivity (ln σ) and ln nFk 0 , indicating that the bulk ion conduction in the solid-state electrolyte is the rate-determining step. , As a result, selecting solid-state electrolytes with high ionic conductivity and assisting with appropriate interfacial modification is crucial for the construction of high-performance FIBs.…”