Vinylene Carbonate and Li Salicylatoborate as Additives in LiPF[sub 3](CF[sub 2]CF[sub 3])[sub 3] Solutions for Rechargeable Li-Ion Batteries

Merck KGaA developed (LiFAP) as a new electrolyte that can replace the commonly used in Li-ion batteries. Vinylene carbonate and Li salicylato borate (Merck's AD25) were studied as additives for LiFAP solutions in mixtures of ethylene, dimethyl, and diethyl carbonates with composite graphite and electrodes. The tools for this study included voltammetry (fast and slow scan rates), chronopotentiometry, impedance spectroscopy, electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. It was found that LiFAP solutions containing VC were superior for both graphite and (spinel) electrodes. The effect of additives on the electrodes' performance can be clearly attributed to their impact on the surface chemistry of these electrodes. © 2003 The Electrochemical Society. All rights reserved.