Synergistic Role of Electrolyte and Binder for Enhanced Electrochemical Storage for Sodium-Ion Battery

Sodium-ion batteries are promising futuristic large-scale energy-storage devices because of the abundance and low cost of sodium. However, the development and commercialization of the sodium-ion battery solely depends on the use of high-capacity electrode materials. Among the various metal oxides, SnO₂ has a high theoretical specific capacity for sodium-ion battery. However, the enormous volume expansion and low electrical conductivity of SnO₂ hinder its capability to reach the predicted theoretical value. Although different nanostructured designs of electrode materials like SnO₂ nanocomposites have been studied, the effects of other cell components like electrolyte and binder on the specific capacity and cyclic stability are yet to be understood. In the present study, we have investigated the synergistic effect of electrolyte and binder on the performance enhancement of SnO₂ supported on the intertwined network structure of reduced graphene oxide partially open multiwalled carbon nanotube hybrid as anode in sodium-ion battery. Our result shows that sodium carboxyl methyl cellulose and ethylene carbonate/diethyl carbonate as the electrolyte solvent offers a high specific capacity of 688 mAh g^-1 and a satisfactory cyclic stability for 500 cycles. This is about 56% enhancement in specific capacity compared to the use of poly(vinylidene fluoride) binder and propylene carbonate as the electrolyte solvent. The present study provides a better understanding of the synergistic role of electrolyte and binder for the development of metal-oxide-based electrode materials for the advancement of the commercialization of sodium-ion battery.