▎ 摘　　要

NOVELTY - An electrolyte comprises 1.5-3 M lithium difluoro(oxalato)borate (LiDFOB) and a carbonate solvent. USE - Electrolyte used for rechargeable battery (claimed) e.g. lithium metal rechargeable battery. Uses include but are not limited to mobile phone, smart phone, laptop, tablet, digital camera, camcorder, electronic cigarette, handheld game console, flashlight, car, motorcycle, hybrid vehicle, electric motorcycle, scooter, electric bicycle, personal transporter, electric wheelchair, radio-controlled model, and model aircraft. ADVANTAGE - The electrolyte has high concentration of lithium difluoro(oxalato)borate (LiDFOB) and carbonate solvent, thus conferring high cycling performance. The rechargeable battery comprising the electrolyte may have a high capacity of up to 2.8 Ah, and has a capacity retention of 65% for an anode-free battery after 100 cycles or 70% for a battery with a lithium metal anode after 200 cycles. It has a high cycling stability even when heated to a temperature of greater than or equal to 80 degrees C. A cell operating at elevated temperatures with electrolyte, may exhibit 5-50% higher specific capacity and 50% lower electrochemical impedance than a cell operated at room temperature. It may facilitate reversible and smooth lithium plating of a counter electrode on the anode side. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a rechargeable battery; and (2) preparation of the electrolyte.