A Lithium‐Ion Battery with Enhanced Safety Prepared using an Environmentally Friendly Process

A new lithium‐ion battery chemistry is presented based on a conversion–alloying anode material, a carbon‐coated Fe‐doped ZnO (TMO‐C), and a LiNi 1/3 Mn 1/3 Co 1/3 O 2 (NMC) cathode. Both electrodes were fabricated using an environmentally friendly cellulose‐based binding agent. The performance of the new lithium‐ion battery was evaluated with a conventional, carbonate‐based electrolyte (ethylene carbonate:diethyl carbonate–1  m lithium hexafluorophosphate, EC:DEC 1  m LiPF 6 ) and an ionic liquid (IL)‐based electrolyte ( N ‐butyl‐ N ‐methylpyrrolidinium bis(trifluoromethanesulfonyl)imide–0.2  m lithium bis(trifluoromethanesulfonyl)imide, Pyr 14 TFSI 0.2  m LiTFSI), respectively. Galvanostatic charge/discharge tests revealed a reduced rate capability of the TMO‐C/Pyr 14 TFSI 0.2  m LiTFSI/NMC full‐cell compared to the organic electrolyte, but the coulombic efficiency was significantly enhanced. Moreover, the IL‐based electrolyte substantially improves the safety of the system due to a higher thermal stability of the formed anodic solid electrolyte interphase and the IL electrolyte itself. While the carbonate‐based electrolyte shows sudden degradation reactions, the IL exhibits a slowly increasing heat flow, which does not constitute a serious safety risk.