Fluorine‐Free Lithium Battery Using Boron‐Based Salt and Glyme Solvent

The present battery technology includes fluorine in electrodes and electrolytes, which is one of the most challenging environmental issues, possibly leading to polyfluoroalkyl substances (PFAS) pollution. Herein, we investigate the features of a fully fluorine‐free battery using lithium iron phosphate (LiFePO 4 , LFP) electrode, polyethylene oxide (PEO) binder, and lithium bis(oxalate)borate (LiBOB) salt. The salt is incorporated both in the electrode by environmental friendly aqueous processing, and in the electrolyte exploiting a glyme solvent. The electrolyte reveals conductivity higher than 1 × 10 −3 S cm −1 from 60 to −2°C, lithium transference number ( t Li + ) of 0.57, electrochemical stability extending from 0 to 4.3 V versus Li + /Li, low stripping/deposition polarization and interphase resistance. The electrode shows high crystallinity, adequate morphology and thickness, low tortuosity, and enhanced Li + ‐percolation, decreasing the cell polarization. Furthermore, the PEO binder and the absence of organic solvents during electrode preparation enable LFP loading as high as 13.6 mg cm −2 , with maximum discharge capacity at 3.5 V of ~160 mAh g −1 (2.15 mAh cm −2 ). Therefore, this work presents a viable design of new fluorine‐free water‐processed electrodes and boron‐based glyme electrolyte solutions, which are essential for the development of high‐performing rechargeable Li‐metal batteries (LMBs) having a low environmental impact.