Boosting Li-O2 Battery Performance via Coupling of P-N Site-Rich N, P Co-Doped Graphene-Like Carbon Nanosheets with Nano-CePO4

Abstract

Development of efficient and robust cathode catalysts is critical for the commercialization of Li-O₂ batteries (LOBs). Herein, a well-designed CePO₄ @N-P-CNSs cathode catalyst for LOBs via coupling P-N site-rich N, P co-doped graphene-like carbon nanosheets (N-P-CNSs) with nano-CePO₄ via a novel "in situ derivation" coupling strategy by in situ transforming the P atoms of P-C sites in N-P-CNSs to CePO₄ is reported. The CePO₄ @N-P-CNSs exhibit superior bifunctional ORR/OER activity relative to commercial Pt/C-RuO₂ with an overall overpotential of 0.64 V (vs RHE). Moreover, the LOB with CePO₄ @N-P-CNSs as the cathode catalyst delivers a low charge overpotential of 0.67 V (vs Li/Li⁺ ), high discharge capacity of 29774 mAh g^-1 at 100 mA g^-1 and long cycling stability of 415 cycles, respectively. The remarkably enhanced LOB performance is attributable to the in situ derived CePO₄ nanoparticles and the P-N sites in N-P-CNSs, which facilitate increased bifunctional ORR/OER activity, promote the rapid and effective decomposition of Li₂ O₂ and inhibit the formation of Li₂ CO₃ . This work may provide new inspiration for designing efficient, durable, and cost-effective cathode catalysts for LOBs.

Keywords: CePO 4; Li-O 2 batteries; N, P co-doped graphene-like nanosheets; bifunctional ORR/OER activity; cathode catalysts.