Impact of 3‐Cyanopropionic Acid Methyl Ester on the Electrochemical Performance of ZnMn2O4 as Negative Electrode for Li‐Ion Batteries

Due to their high theoretical capacity, transition metal oxide compounds are promising electrode materials for lithium‐ion batteries. However, one drawback is associated with relevant capacity fluctuations during cycling, widely observed in the literature. Such strong capacity variation can result in practical problems when positive and negative electrode materials have to be matched in a full cell. Herein, the study of ZnMn2O4 (ZMO) in a nonconventional electrolyte based on 3‐cyanopropionic acid methyl ester (CPAME) solvent and LiPF6 salt is reported for the first time. Although ZMO in LiPF6/CPAME electrolyte displays a dramatic capacity decay during the first cycles, it shows promising cycling ability and a suppressed capacity fluctuation when vinylene carbonate (VC) is used as an additive to the CPAME‐based electrolyte. To understand the nature of the solid electrolyte interphase (SEI), the electrochemical study is correlated to ex situ X‐ray photoelectron spectroscopy (XPS). A 3‐cyanopropionic acid methyl ester (CPAME)‐based electrolyte with vinylene carbonate (VC) additive can effectively suppress capacity fluctuations of conversion/alloying‐type metal oxide negative electrode (ZnMn2O4) in Li‐ion batteries (LIBs). Together with its lower safety issues with respect to conventional solvents used in LIBs, CPAME is a promising solution to the development of stable systems based on conversion materials.