Rational Design of Interlayer Binding Towards Highly Reversible Anion Intercalation Cathode for Dual Ion Batteries

Abstract

Dual-ion batteries (DIBs) with high working voltages and energy densities have gained more and more attention these years. However, general graphitic intercalation compounds (GICs) still require substantial improvements in both cathode practical capacity and structural stability. In this work, rational edge carboxylic anhydride functionality is introduced between carbon layers. One of the advantages is to expand the interlayer stacking, significantly improving active site accessibility and enhancing anion intercalation kinetics. Moreover, it can also serve as strong binding forces within interlayers, which can effectively prevent interlayer exfoliation during repeated anion intercalation/deintercalation. Benefited from this rational design, the carboxylic anhydride functionalized graphitic cathode is able to improve discharge capacity by over 37% with no obvious voltage deduction. Meanwhile the capacity retention of over 80% after 1000 cycles is achieved. Overall, this work reveals an effective way to improve both energy density and longevity of the graphite cathodes for dual ion batteries.