Toward wide‐temperature electrolyte for lithium–ion batteries

Abstract

Lithium-ion battery (LIB) suffers from safety risks and narrow operational temperature range in despite the rapid drop in cost over the past decade.Subjected to the limited materials choices, it is not feasible to modify the cathode and anode to improve the battery's wide-temperature performance, hence, optimizing the design of the electrolyte system has currently become the most feasible and economical way to broaden the operating temperature range of LIBs. Considering urgent demands for wide-temperature LIBs and achieved enormously excited results about wide-temperature electrolytes in recent years, a review about this topic and scope is timely and important at present. In this study, we first examine the physicochemical properties of current commercial electrolytes with emphasis on the variations of key parameters along with the temperature.After that, we give comprehensive overview of the employed strategies for separately improving the electrochemical performance of electrolytes toward low-temperature, high-temperature, and wide-temperature applications. Furthermore, recent progress of ionic liquids and solidstate electrolytes that are capable of working within wide temperature range is also summarized. We hope this review will provide deep understanding of the design principles of wide-temperature electrolyte, and inspire more endeavors to conquer the practicability issue of LIBs in extreme environments.

A Review on Regulating Li+Solvation Structures in Carbonate Electrolytes for Lithium Metal Batteries

“…[47] However, their low solubility has hindered their use as the main salts of carbonate electrolytes and LiDFOB is more used as an additive. [34,[59][60][61] Lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) and lithium bis(fluorosulfonyl)imide (LiFSI) are alternative Li salts in carbonate electrolytes, but they corrode the current collector of the cathode aluminum (Al) at high voltages, restricting their use in dilute carbonate electrolytes. [62] Fortunately, it is avoided in HCEs and LHCEs without free solvents dissolving Al 3+ , [63] thus along with the desirable solubility and film-forming capability of LiTFSI and LiFSI, they have been extensively investigated in HCEs and LHCEs.…”

“…[28,89,90] When reaching the low-temperature regime, with the dramatic increase of the viscosity of the electrolyte, the ionic conductivity and de-solvation kinetics which are highly determined by the Li + solvation structure become dominant factors affecting the kinetics of the battery. [14,34] If free solvents remaining near the interface after de-solvation are electrochemically unstable, they can be decomposed and decrease the battery performance (Figure 2i). [50] Therefore, it is important to develop a solvation structure that is not only able to induce the formation of inorganic-rich stable interfaces but also stable and kinetically favorable in the bulk electrolyte and against both electrodes.…”

“…[32] Also, when widening the operating temperature range of the batteries, the solvation structures have a more significant effect on the overall performance of the electrolyte. For example, LiPF 6 decomposition becomes more vigorous with increasing temperature while Li + migration and de-solvation become more sluggish at low temperatures, [14,26,33,34] all of which are highly related to the solvation structure of Li + (Figure 1). Therefore, a systematic understanding of the solvation structure and its regulation strategies in LMBs can not only provide a timely overview of the latest developments in research but also provide guidance for rationally designing an electrolyte with outstanding performance in all respects.…”

Strong Solvent and Dual Lithium Salts Enable Fast-Charging Lithium-Ion Batteries Operating from −78 to 60 °C

“…To ensure high ionic conductivity even under ultralow temperatures (< −50 °C), DMS with an extremely low freezing point of −141 °C and a high dielectric constant of 22.5 (Figure a) was chosen as the sole solvent (Table S1). − Density functional theory (DFT) calculations were employed to determine the binding energies between different anions and Li + ions (Figure b). LiFSI was chosen as the dominant lithium salt due to its strong dissociation ability, which allows fast Li + conduction when paired with the DMS solvent even under ultralow temperatures.…”

Bismuth nanoparticles embedded in a carbon skeleton as an anode for high power density potassium-ion batteries

“…1 One of the effective strategies is to increase the share of renewable clean energy (such as wind, solar, and geothermal resources) in the electric energy structure. [2][3][4][5][6] However, renewable clean energy is generally intermittent, so its development closely depends on large-scale energy storage/conversion systems. [7][8][9] Recently, potassium-ion batteries (PIBs) have been considered as promising candidates for this purpose due to the high abundance of potassium resources and low redox potential of K + /K in an organic electrolyte (À2.93 V vs. the standard hydrogen electrode).…”