Water‐Soluble Green Binder for Li4Ti5O12 Anodes: Effect of Binder Choice on Lithium Storage

Abstract

AbstractThis study mainly focuses on the effect of newly identified water‐soluble green binder, LA132, on the lithium storage properties of the Li4Ti5O12 (LTO) anode in comparison with that of conventionally used non‐aqueous PVdF binder. Herein, the electrochemical behavior of the LTO anode is significantly improved with the LA132 binder to the extent that better cyclability (100 cycles), appreciable rate capability (20 C), and enhanced cycle life behavior (200 cycles) at 1 C have been demonstrated. Such an excellent electrochemical performance of LTO/LA132 assembly over that of LTO/PVdF could be correlated with the enhanced lithium‐ion transport kinetics (3.0×10−12 cm2 s−1), resulting from the narrow and uniform coverage of LA132 binder on the surface of LTO particles as well as on the conductive carbon, as evidenced by XPS and SEM analyses, thus demonstrating the possibilities of realizing high lithium‐ion mobility and absence of electrode fracture, especially upon extended cycles. In addition, EIS and contact angle measurements clearly evidence that the LTO anode with LA132 binder shows a lower charge‐transfer resistance (50.23 Ω), lower apparent activation energy (27.5 KJ mol−1), good wettability with the electrolyte, and lower apparent diffusion activation energy (41.5 KJ mol−1) compared with that of LTO and PVdF binder. We believe that the newly investigated water‐based LA132 binder for LTO anodes paves the way to the demonstration of low‐cost and green lithium‐ion technology.