Tailoring electrolyte solvation for Li metal batteries cycled at ultra-low temperature

Abstract

Lithium metal batteries (LMBs) hold the promise to pushing cell level energy densities beyond 300 Wh kg −1 while operating at ultra-low temperatures (< −30°C). Batteries capable of both charging and discharging at these temperature extremes are highly desirable due to their inherent reduction of external warming requirements. Here we demonstrate that the local solvation structure of the electrolyte defines the charge-transfer behavior at ultra-low temperature, which is crucial for achieving high Li metal coulombic efficiency (CE) and avoiding dendritic growth. These insights were applied to Li metal full cells, where a high-loading 3.5 mAh cm −2 sulfurized polyacrylonitrile (SPAN) cathode was paired with a one-fold excess Li metal anode. The cell retained 84 % and 76 % of its room temperature capacity when cycled at −40 and −60 °C, respectively, which presented stable performance over 50 cycles. This work provides design criteria for ultra-low temperature LMB electrolytes, and represents a defining step for the performance of low-temperature batteries.

Effectively Regulating More Robust Amorphous Li Clusters for Ultrastable Dendrite‐Free Cycling

“…[ 57 , 58 , 59 , 60 ] These uniform and rapid Li ion diffusion on this advanced, orderly, and robust SEI contribute to sustain enough mass transport of Li ions near the electrolyte–electrode interface, and the homogeneous Li depositions can be obtained. [ 61 , 62 , 63 ] This SEI is smooth and has high mechanical strength, ensuring effective improvements of the electrode reversibility, interface stability, and uniformity of Li deposition. Thus, an ultrastable dendrite‐free deposition of homogeneous ALi is effectively regulated on this advanced, multilayer‐ordered, and robust SEI for a more robust ALi cluster anode.…”

Toward Low‐Temperature Lithium Batteries: Advances and Prospects of Unconventional Electrolytes

“…In contrast, it has demonstrated that the solvation structure of the electrolyte deeply affects the charge-transfer behavior at low temperature. [25] The performance was mainly influenced by the interfacial ion desolvation mechanics and the corresponding Li deposition morphologies. Finally, the LMBs are able to improve the Columbic efficiency with decreasing dendritic growth.…”

A Desolvation‐Free Sodium Dual‐Ion Chemistry for High Power Density and Extremely Low Temperature

“…Low-temperature performance loss of graphite-based LIBs is an issue that researchers are pursuing to address all the time. [5,12] Thel imited charge capacity of LIBs (or discharge capacity of graphite) at subzero temperature is mainly attributed to as luggish desolvation process at the graphite interphase,the dominant impedance contributor. [7,12] Therefore,u tilizing co-intercalation of solvents is undoubtedly astraightforward way to circumvent such abig obstacle.…”

“…[5,12] Thel imited charge capacity of LIBs (or discharge capacity of graphite) at subzero temperature is mainly attributed to as luggish desolvation process at the graphite interphase,the dominant impedance contributor. [7,12] Therefore,u tilizing co-intercalation of solvents is undoubtedly astraightforward way to circumvent such abig obstacle. To prove the strategy,t he low-temperature operation of the AG anode with Na + -ether co-intercalation mechanism is further investigated, whose capacity maintains 50 %a t 0.1 Ag À1 (1C-rate) and 43 %w ith 0.3 Ag À1 at À40 8 8Cw hen compared to the capacity at 25 8 8C(Figure S16).…”