ZnSe/CoSe/NCDPH composites as anode materials for lithium ion batteries with high capacity and long cycle

In this paper, dopamine hydrochloride (DPH) is introduced to synthesize ZIF-8@ZIF-67@DPH in the preparation of ZIF-8@ZIF-67. ZnSe/CoSe/NCDPH (N-doped carbon) composites are calcined in a high-temperature inert atmosphere with ZIF-8@ZIF-67@DPH as the precursor, selenium powder as the selenium source. ZnSe/CoSe/NCDPH has high discharge specific capacity, good cycle stability and outstanding rate performance. The first discharge capacity of ZnSe/CoSe/NCDPH is 1616.6 mAh g(-1) at the current density of 0.1 A g(-1), and the reversible capacity remains at 1214.2 mAh g(-1) after 100 cycles, the reversible capacity is 416.7 mAh g(-1) after 1000 cycles at 1 A g(-1). Therefore, ZnSe/CoSe/NCDPH composites provide a new step for the research and synthesis of new stable, high-capacity, and safe high-performance lithium ion batteries. The bimetallic selenide composites not only have bimetallic active sites, but also can form synergistic effect between different metal phases, which can effectively reduce the capacity attenuation caused by volume expansion and reactive stress enrichment during lithium storage of metal oxide anode materials. Meanwhile, N-doped carbon can improve the conductivity and provide more active sites to store lithium, thus improving its lithium storage capacity. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

In this study, dopamine hydrochloride was introduced to synthesize ZIF-8@ZIF-67@DPH for the preparation of ZnSe/CoSe/NCDPH composites, which exhibit high discharge specific capacity, good cycle stability, and outstanding rate performance. The bimetallic selenide composites show promising potential for new stable, high-capacity, and safe high-performance lithium ion batteries.