One-pot synthesis of boron-doped cobalt oxide nanorod coupled with reduced graphene oxide for sodium ion batteries

Heteroatom doping is one of the feasible strategies to improve electrode efficiency. Meanwhile, graphene helps to optimize structure and improve conductivity of the electrode. Here, we synthesized a composite of boron-doped cobalt oxide nanorods coupled with reduced graphene oxide by a one-step hydrothermal method and investigated its electrochemical performance for sodium ion storage. Because of the acti-vated boron and conductive graphene, the assembled sodium-ion battery shows excellent cycling stabil -ity with a high initial reversible capacity of 424.8 mAh g-1, which is maintained as high as 444.2 mAh g-1 after 50 cycles at a current density of 100 mA g-1. The electrodes also exhibit excellent rate performance with 270.5 mAh g-1 at 2000 mA g-1, and retain 96% of the reversible capacity upon recovery from 100 mA g-1. This study shows that boron doping can increase the capacity of cobalt oxides and graphene can stabilize structure and improve conductivity of the active electrode material, which are essential for achieving satisfactory electrochemical performance. Therefore, the doping of boron and introduction of graphene may be one of the promising means to optimize the electrochemical performance of anode materials. (c) 2023 Elsevier Inc. All rights reserved.