N/S co-doped CoSe/C nanocubes as anode materials for Li-ion batteries

Lifeng Cui,Haoyu Qi,Chunyu Song,Jinghua Yang,Gang Wang,Xin Gao,Shifeng Kang,Nannan Wang,Xiaodong Chen

doi:10.1515/ntrev-2022-0018

Abstract

Abstract The transition metal selenide can be used as a potential material for the negative electrode of lithium-ion batteries (LIBs) owing to its high density and conductivity. Unfortunately, a large volume change occurs in the transition metal selenide during the charging and discharging process, which eventually results in the poor rate performance and rapid capacity decay. In response to this, the N/S co-doped CoSe nanocubes (CoSe/C–NS) can be fabricated where the S-doped cobalt 2-methylimidazole (ZIF-67) as both sacrifice template and cobalt source to directly mix with selenium powder and followed by the annealing process. In the process, the carbon frameworks derived from ZIF-67 can establish a coating layer to protect the structure of materials, and simultaneously the N/S co-doping can enhance the conductivity and broaden the interlayer of frameworks. These can further accelerate the storage capacity and the Li+ insertion and deintercalation process. As a negative electrode material of LIBs, the CoSe/C–NS delivers the high capacity, high rate performance, and long-term cycle stability. This protocol opens up an approvable approach to fabricate efficient anode materials with persistent electrochemical stability in LIBs.

Highlights

In the past few decades, the ever-growing energy shortage has triggered the widespread concern due to the limitation of non-renewable fossil energy
The lithium-ion batteries (LIBs) with the advantage of environmental friendliness are regarded as the alternative energy equipment that contribute to the transformation of these unstable electrical energies into stable
An N-doped and S-doped (N/S co-doped) carbon box-shaped material which uses a kind of S-doped metal–organic frameworks (MOFs) (S-doped ZIF-67) as a template and is etched by HCl has been impressively carried out for potassium storage [19]

Summary

Introduction

In the past few decades, the ever-growing energy shortage has triggered the widespread concern due to the limitation of non-renewable fossil energy. An N-doped and S-doped (N/S co-doped) carbon box-shaped material which uses a kind of S-doped MOFs (S-doped ZIF-67) as a template and is etched by HCl has been impressively carried out for potassium storage [19] This is because S-doped ZIF-67 could introduce more defects and widen the interlayer spacing of carbon-based materials, thereby improving storage capacity and conductivity. ZIF-67-based CoSe/C nanocomposites with N-doped have been reported as electrodes for supercapacitors, which presented good electrochemical performance [20] These aforementioned advantages exist in the N/S-doped ZIF-67 derived CoSe/C nanocomposite materials, it is believed that there have been rare investigations on them as anode materials for LIBs. To date, it is reported that only ZIF-67-derived CoSe/C is utilized for the anode of LIBs [21]. As the anode material of LIBs, the CoSe/C–NS has a high specific capacity of 1,494 mA h/g after 300 cycles at a current density of 0.2 A/g, and the CoSe/C–NS shows excellent performance at high current density, which demonstrates that S-doped material has better comprehensive performance such as structural stability than CoSe/C–N nanocomposite assembled in LIBs

Synthesis of S-ZIF-67

Materials characterization

Electrochemical measurements

Results and discussion

Conclusion