Sulfone additive enhanced ultrahigh energy density Li/CFx primary batteries

• Published in: Journal of power sources Vol. 630; p. 236098
• Main Authors: Zhang, Huajun, Zou, Jilong, Shen, Zongnan, Liu, Zhimeng, Hu, Linyu, Yue, Hongjun, Chen, Huixin, Wu, Yuheng, Huang, Shengtao, Li, Zongjun, Chen, Jing, Geng, Xin, He, Xin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 28.02.2025
• Subjects: Dual discharge platforms; Electrolyte additive; High energy density; Primary batteries; Sulfolane; Primary batteries; Sulfolane; Electrolyte additive; Dual discharge platforms; High energy density
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2024.236098

Lithium/fluorinated-carbon (Li/CFx) primary batteries have been widely used for consumer electronics, medical and military devices because of their high energy density and low self-discharge rate. However, their intrinsic energy is limited by the large electrochemical overpotential at high discharge currents, which impedes fully utilization of energy under high-power requirement. In this work, sulfolane (SL) is employed as an additive for sulfite-based electrolyte to promote the discharge capacity and boost the rate capability. The anion-paired solvation structure is enhanced to facilitate the desolvation of Li-ions during the charge transfer process. Additionally, the C-F covalent bond is weakened, promoting the reaction between the solvated Li-ions with CFx, which increases the participation of CFx in the electrochemical reaction. As a result, the SL containing electrolyte enables superior electrochemical performance of Li/CFx battery, delivers an energy density of 2556.5 kW kg−1 with two discharge plateaus and a capacity of 525 mAh g−1 at the current rate of 10C. This work holds great promise for high-performance Li/CFx batteries in practical applications, and provide guidance for future electrolyte design. •Sulfone additive for sulfite-based electrolyte for Li/CFx primary batteries is proposed.•Sulfone additive helps sulfite-based electrolyte break through the theoretical capacity of CFx.•MD simulations compliment experiment results with insight into Li-ions transportation.•In-situ XRD reveals the internal structural changes of CFx.