A simple approach to minimize the first cycle irreversible loss of sodium titanate anode towards the development of sodium-ion battery

First cycle irreversible loss is a major problem of any kind of anode materials in sodium-ion battery systems (SIBs). Here, we present a stable (4000 cycles), high capacity (237 mAh g(-1)) and high rate capable hydrogenated metal-doped sodium titanium oxide (Na2Ti3O7) anode material for SIBs and that suffers from high 1st cycle irreversible loss (53.86%) initially. Later, we adopted a simple chemical shorting approach where, sodium metal was kept immediate tight contact with anode material in presence of electrolyte medium to reduce the irreversible loss. It was found that 60 min chemical shorting is enough to minimize the irreversible loss to 4.11% from 53.6% and enhance the Coulombic efficiency to 84% from 36.22% respectively without compromising the specific capacity and cycling stability. This approach is adopted in full-cell (sodium vanadium phosphate vs. hydrogenated metal-doped Na2Ti3O7) formation and the study also provided similar improved electrochemical performance. The current understanding and the approach provide a new direction to overcome the 1st cycle irreversible loss of sodium titanate anode and can be utilized further to develop sustainable rechargeable sodiumion battery.