Enabling Sodium Compensation, Stable CEI Formation and Fast‐Charging Using Thiocarbamate Additive in NVP Cathodes

To overcome the instability of sodium‐ion cathode materials due to sodium losses and an unstable cathode electrolyte interface, the cathode additive method is an efficient approach; however, finding a cost‐effective additive with a low decomposition potential remains a challenge. This work identifies a sodium salt of thiocarbamate as an appropriate sodium compensating reagent. The thiocarbamate salt was found to effectively decompose into an amorphous N, S‐rich CEI at low voltage, simultaneously compensating for the sodium losses during cycling. When introduced as an additive to Na 3 V 2 (PO 4 ) 3 cathode, an addition of 10 wt.% extends the discharge capacity, charging behavior, and stability of the cathode. In the full cells, the use of the additive increases the energy density from 72.32 to 131.43 Wh kg −1 , indicating great prospects of thiocarbamate functionality in revitalizing sodium‐ion batteries for practical purposes.