Se/N co-doped carbon nanorods for potassium ion storage

Abstract

Herein, we make use of the large-sized Se atom to regulate the local structure of the graphitic lattice to optimize N-doping species to strengthen the adsorption of K⁺, which can greatly boost the capacitive capacity for potassium ion batteries. The resulting Se/N co-doped carbon nanorods (SeNCRs) retain a reversible capacity of 303 mA h g⁻¹ at 0.1 A g⁻¹ after 100 cycles, and exhibit long-term cycling performance with a capacity of 198.6 mA h g⁻¹ at 2 A g⁻¹ after 3000 cycles. Electrochemical characterizations confirm the existence of the capacitive capacity in the SeNCRs for potassium ion batteries, and corresponding physical characterizations show that the SeNCRs have a stable structure that can tolerate the reversible intercalation/deintercalation of K⁺.