High-Voltage Sulfolane Plasticized UV-Curable Gel Polymer Electrolyte

Abstract

A high-voltage electrolyte can match high-voltage positive electrode material to fully exert its capacity. In this research, a sulfolane plasticized polymer electrolyte was prepared by in situ photocuring. First, the effect of the sulfolane content on the ionic conductivity of the gel polymer electrolyte was investigated. Results showed that the ionic conductivity variation trend was in good agreement with the exponential function model for curve fitting. Second, the activation energy was calculated from the results of the variable temperature conductivity tests. The activation energy was inversely proportional to the sulfolane content. For the sulfolane content of 80 wt. % in gel polymer electrolyte (GPE)-80 (19.5 kJ/mol), the activation energy was close to conventional liquid electrolyte (9.5 kJ/mol), and the conductivity and electrochemical window were 0.64 mS/cm and 5.86 V, respectively. The battery cycle performance test showed that the initial specific discharge capacities of GPE-80 and liquid electrolyte were 176.8 and 148.3 mAh/g, respectively. After 80 cycles, the discharge capacities of GPE-80 and liquid electrolyte were 115.8 and 41.1 mAh/g, and the capacity retention rates were 65.5% and 27.7%, respectively; indicating that GPE-80 has a better specific discharge capacity and cycling performance than the liquid electrolyte. SEM images indicated that GPE-80 can suppress the growth of lithium dendrites. The EDS test showed that GPE-80 can inhibit the dissolution of metal ions in the cathode material.

Are Polymer‐Based Electrolytes Ready for High‐Voltage Lithium Battery Applications? An Overview of Degradation Mechanisms and Battery Performance

“…[176] The ionic liquids have possibly even higher oxidative stability, [177] and this property is normally retained in ionic liquid-containing GPEs. [80] Alternative organic solvents with high oxidative stability include fluorinated solvents, [178,179] phosphates, [180] sulfolane, [181][182][183] and nitrile-containing additives, such as succinonitrile (SN). [184] Interestingly, the enhanced oxidative stability can be observed in certain GPEs containing polymer blends, which can be attributed to an intermolecular interaction between a "functional" polymer and the cathode or the additional electrolyte components.…”

“…EDS is particularly useful for detecting transition metal‐ion cross‐talk in HVLP cells: transition metal ions dissolved from the cathode and deposited on the anode can be detected by conducting the EDS analysis on cycled Li‐metal anodes. [ 143,182 ]…”

A Multifunctional Dual‐Salt Localized High‐Concentration Electrolyte for Fast Dynamic High‐Voltage Lithium Battery in Wide Temperature Range

“…Therefore, it is more important to develop an electrolyte that can be compatible with high‐voltage materials in wide temperature range. The sulfone solvent [ 12 ] is expected to be an ideal solvent for high‐voltage electrolyte due to its low price and high oxidation stability. Tan et al.…”

Functional additives for solid polymer electrolytes in flexible and high‐energy‐density solid‐state lithium‐ion batteries

“…The results showed that the oxidation potentials of GPE-40, GPE-60, and GPE-80 were 6.01, 5.96, and 5.86 V, respectively, showing great potential for use on high-voltage cathode materials. 86 The ceramic additives show excellent capability to improve the electrochemical or thermal stability of SPEs. Normally, the bare PEO film is electrochemically oxidized at around 4.0 V (vs. Li/Li + ) at 30°C and shows a narrow electrochemical window below 4.5 V. However, with the addition of 5 wt% Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 (LATP) to the PEO polymer, the electrochemical window can be increased to 4.8 V, which is attributed to the wide electrochemical window of LATP (Figure 9E).…”