Investigating alternate binders: Impact on the performance of lithium titanate anode.

Rechargeable Li-ion batteries although efficiently power small portable devices, implementation in electric vehicle mobility to assuage environmental concerns demand batteries possessing higher power densities and capacities while being compact and safer. Recent research is hence focused towards developing battery components that can sustain high charge-discharge rates while comprehensively addressing the safety issues. In our present research effort, attempts are made to investigate the role of different binders on the performance of nanostructured lithium titanate (LTO, Li4Ti5O12) anodes in half-cell configuration against Li-metal. Commercial nano-LTO, Super-P and polyvinylidene fluoride (PVdF) are used as reference materials for comparative appraisal. An endeavor is made to showcase the feasibility of water soluble binders: sodium alginate (Na-alginate) and sodium carboxymethyl cellulose (Na-CMC) for greener processing of the electrodes and evaluate the effect on specific capacity, reversibility, charge retention and adaptability towards faster charging rate in the half-cells assembled. Binders provide sufficient adhesion interconnecting the active particles as well as maintain proper contact with the current collector, thus imparting electrode integrity over multiple charge-discharge cycles. This apart, binders are understood to influence the conductivity of electrodes, electrolyte wetting behavior, formation of solid-electrolyte interface (SEI) and the charge-transfer across interfaces. A lower interfacial resistance can promote higher specific capacity, increase energy density, improve reversibility, etc. while restricting capacity fade even at high C-rates; and the role of binders is found to contribute significantly. Comprehensive analysis of electrochemical impedance data collected at the end of each galvanostatic charge/discharge cycle provided crucial clues in understanding the charge transfer behavior for the electrodes fabricated with the binders. [ABSTRACT FROM AUTHOR]