Cyclodextrin polymers as effective water-soluble binder with enhanced cycling performance for Li2ZnTi3O8 anode in lithium-ion batteries

Polymeric binders play an important role in maintaining the integrity of electrodes and improving the electrochemical performance of batteries. Unlike binders soluble in organic solvents, water-soluble binders are environmentally friendly and easy to recycle. In this work, a comparative study on the effects of water-soluble cyclodextrin and organic-based PVDF binders on the Li+ intercalation/deintercalation of lithium-ion batteries with Li2ZnTi3O8 anode is conducted for the first time. Compared to α-cyclodextrin, γ-cyclodextrin, and PVDF, LZTO with β-cyclodextrin binder exhibits larger Li+ storage capacity, better cycle stability, rate capability, and higher Coulombic efficiency, possessing a high electrical conductivity, low charge transfer resistance, and fast lithium-ion diffusion coefficient. β-Cyclodextrin water-soluble binder not only makes the active material difficult to separate from the current collector and facilitates favorable electrochemical kinetics but also maintains good cycle stability at high temperatures. Utilizing these advantageous features, β-Cyclodextrin-based LZTO electrode shows markedly improved reversible Li+ storage performance compared to those of other binder cases.Graphical abstract