B−N Co‐Doped Biphenylene as a Metal‐Free Cathode Catalyst for Li−O2 Batteries: a Computational Study

Abstract

AbstractLithium‐oxygen batteries (LOBs) meet the growing demand for long‐distance transportation over electric vehicles but face challenges because of the lack of high‐performance cathode catalysts. Herein, using density functional theory calculations, we report a unique graphene allotrope, biphenylene, of which the doping structures exhibit great potential as metal‐free catalysts for LOBs. Our modeling results demonstrate that the biphenylene nanosheets retain metallic properties after B doping, N doping, or B−N co‐doping. Compared with the pristine biphenylene, the catalytic activity of the doped biphenylene is greatly improved due to charge redistributions. Notably, the overpotentials of the B−N co‐doped biphenylene are as low as 0.19 and 0.18 V for the discharge and charge processes, respectively. Based on the electronic structure and bonding analysis, we identify two factors, i. e., Li−O bond strength and *Li2O2 adsorption energy, that can influence the Li−O2 electrochemical reactions. This study not only proposes a promising cathode catalyst but also provides insights into optimizing cathode catalysts for LOBs.