ZnTe/rGO Composite as the Fully Zinced Conversion‐Type Cathodes for Aqueous Zinc Ion Batteries**

Abstract

Conversion‐type cathodes for aqueous zinc ion batteries (ZIBs) can provide flat plateau slop and stable output potential, compared to general intercalation‐type cathodes. The high volumetric capacity and stable output potential of Te make it a promising cathode for ZIBs, but sluggish kinetics and large volume change hinder its further application. To address these issues, we revisit fully zinced ZnTe and construct ZnTe/rGO composites as the new conversion‐type cathode. The electrode undergoes a solid‐to‐solid conversion reaction and shows a stable output potential with ultra‐flat discharge plateau slop of 0.09 V (Ah g−1)−1. When ZnTe is de‐zinced and transformed to Te during charge process, it has a volume shrinkage which generates empty space in graphene matrix for latter volume expansion of Te. The graphene matrix also improves conductivity and reaction kinetics of the cathode. Due to the combination of pre‐zincation of ZnTe, graphene matrix and the elimination of “shuttle effects” process, ZnTe/rGO electrode exhibits a high and stable capacity of 186 mAh g−1 at 500 mA g−1 after 300 cycling, with almost no decay after initial 10 cycles.

Rationally Designed ZnTe@C Nanowires with Superior Zinc Storage Performance for Aqueous Zn Batteries

“…According to the previous report, the conversion of ZnTe in aqueous electrolyte generally undergoes a two‐electron reaction with a theoretical specific capacity of 278 mAh g −1 . [ 32 ] It's worth noting that the ZnTe@C NWs in this study presented a specific capacity of 526 mAh g −1 at 0.1 A g −1 , which is almost two times >278 mAh g −1 . Therefore, the detailed reaction mechanism of ZnTe should be comprehensively investigated.…”

Evolution of Metal Tellurides for Energy Storage/Conversion: From Synthesis to Applications

“…To overcome these challenges, Yi et al. [ 160 ] re‐examined ZnTe and developed ZnTe/rGO composites, serving as new conversion‐type cathodes. This cathode underwent a solid‐to‐solid conversion and presented a stable output potential with a flat discharge plateau of 0.09 V (Ah g −1 ).…”

High Energy Density Aqueous Zinc–Chalcogen (S, Se, Te) Batteries: Recent Progress, Challenges, and Perspective

“…[ 174 ] Another work studying the ZnTe/rGO (reduced Graphene Oxide) composites as the new facile cathode of ZIBs in 2023 was proposed by Li and co‐workers. [ 57 ] As a typical conversion‐type cathode for aqueous ZIBs, these ZnTe/rGO composites were constituted via a facile hydrothermal reaction to synthesize ZnTe polygon in graphene oxide (GO) solution. Owing to the stable conversion‐type mechanism of ZnTe with great conductivity of graphene, the ZnTe/rGO cathode exhibited superior cycling capacity, outstanding rate ability, and flat charge/discharge potential, delivering a capacity of 225 mAh g −1 at 0.1 A g −1 and flat discharge plateau slop of 0.09 V (Ah g −1 ) −1 (Figure 10e–g).…”

“…Up to now, various electrode materials of zinc–sulfur battery, including zinc–selenium (Zn–Se) and zinc–tellurium (Zn–Te) battery, which act as analogs of sulfur in the periodic table, have been constantly investigated due to their appealing theoretical energy densities and ultrahigh physical properties. [ 56,57 ] Noticeably, Liu and co‐workers introduced the advantages and recent progress of aqueous multivalent‐ion batteries based on chalcogen and halogen conversion chemistry. [ 58 ] The wide employment of chalcogen and halogen materials in various aqueous batteries has been summarized systematically in her review, which could be considered as a tremendous effort to pave the way for the further development of high‐performance aqueous multivalent‐ion batteries.…”