Enhanced Electrochemical Properties of KTiOPO4-rGO Negative Electrode for Sodium and Potassium Ion Batteries

Potassium titanyl phosphate (KTiOPO4) is a well-known material for nonlinear optical device applications, but its electrochemical properties are not yet well understood. This study investigates sodium and potassium storage properties of KTiOPO4 using alkali metal fluorosulfonyl amide based nonaqueous electrolytes and a higher stiffness sodium alginate binder. The prepared KTiOPO4- reduced graphene oxide (rGO) composite electrode delivers stable desodiation and depotassiation capacities of 97 and 123 mAh g(-1), respectively, at 0.075 C (10 mA g(-1)) over 70 cycles. The potassium cells demonstrate excellent cycle stability and high rate capability perform-ances. Operando and ex situ XRD measurements confirm the multiple structural changes by potassiation/depotassiation and the high reversibility of the phase evolution.

Automated summary

By using alkali metal fluorosulfonyl amide based nonaqueous electrolytes and a higher stiffness sodium alginate binder, the study prepared a KTiOPO4-reduced graphene oxide composite electrode with stable sodium and potassium storage properties. The research found that this composite electrode exhibited excellent performance during cycling, showing high cycle stability and high rate capability.