Helmholtz Plane Regulation Empowers PF 6 − Permselectivity Towards High Coulombic Efficiency Dual Ion Battery of 5.5 V
Year: 2024
Type: article
Abstract: High‐voltage dual ion battery (DIB) is promising for stationary energy storage applications owing to its cost‐effectiveness, which has been a hot topic of research in rechargeable battery fields. However, it still suffers from rapid battery failure caused by the severe solvent co‐intercalation and electrolyte oxidation. To address these bottlenecks, herein a functional electrolyte additive hexafluoroglutaric anhydride (HFGA) is presented based on a Helmholtz plane regulation strategy. It is demonstrated that the HFGA can precisely enter into the Helmholtz plane and positively regulate anion solvation behaviors near the graphite electrode surface owing to its considerable H−F affinity with ethyl methyl carbonate (EMC), thus alleviating EMC‐related co‐intercalation and oxidation decomposition during DIB charging. Meanwhile, HFGA can copolymerize with the presence of PF 5 at the Helmholtz plane to participate in forming a CF 2 ‐rich CEI layer with excellent PF 6 − permselectivity, conducive to achieving PF 6 − de‐solvation and simultaneously suppressing electrolyte oxidation decomposition. By virtue of such beneficial effects, the graphite cathode enables a 5.5 V DIB with a prominent capacity retention of 92 % and a high average Coulombic efficiency exceeding 99 % within 2000 cycles at 5 C, demonstrating significantly enhanced electrochemical reversibility. The Helmholtz plane regulation strategy marks a milestone in advancing DIB technologies.
Authors: Xiaoqi Han, Hongzhu Jiang, Pengzhou Mu, Wenjun Zhang, Huanrui Zhang, Gaojie Xu, Zheng Chen, Pengxian Han, Guanglei Cui
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W4402278177