Recent Advances in CoSex and CoTex Anodes for Alkali-ion Batteries

Abstract

Transition metal selenides have narrow or zero band-gap characteristics and high theoretical specific capacity. Among them, cobalt selenide and cobalt telluride have some typical problems such as large volume changes, low conductivity, and poor structural stability, but they have become a research hotspot in the field of energy storage and conversion because of their high capacity and high designability. Some of the innovative synthesis, doping, and nanostructure design strategies for CoSex and CoTex, such as CoSe-InCo-InSe bimetallic bi-heterogeneous interfaces, CoTe anchoring MXenes, etc., show great promise. In this paper, the research progress on the multistep transformation mechanisms of CoSex and CoTex is summarized, along with advanced structural design and modification methods such as defect engineering and compositing with MXenes. It is hoped that this review will provide a glimpse into the development of CoSex and CoTex anodes for alkali-ion batteries.

Design of grid-like triple-carbon matrix confined ultrafine CoTe2 nanocrystals toward durable and fast potassium storage

“…14–16 Additionally, the bulky Te 2− anion can serve as a volume-buffering space, which can suppress the volume effect of TMTes during the reaction processes. 16–18 Consequently, TMTes are expected to exhibit faster charge transfer kinetics and reversible electrochemical reactions. 18,19 Despite being promising anode materials for PIBs, TMTes still suffer from short cycle life and poor rate performance, mainly due to the aggregation of active materials during charge/discharge processes and the dissolution and shuttle of intermediates (K 5 Te 3 , K 2 Te) during cycling.…”

“…16–18 Consequently, TMTes are expected to exhibit faster charge transfer kinetics and reversible electrochemical reactions. 18,19 Despite being promising anode materials for PIBs, TMTes still suffer from short cycle life and poor rate performance, mainly due to the aggregation of active materials during charge/discharge processes and the dissolution and shuttle of intermediates (K 5 Te 3 , K 2 Te) during cycling. 9,17,20 Consequently, it is essential to prevent the aggregation of active materials and the dissolution of intermediates in order to improve the overall performance of TMTe anode materials.…”