Activating the Stepwise Intercalation–Conversion Reaction of Layered Copper Sulfide toward Extremely High Capacity Zinc-Metal-Free Anodes for Rocking-Chair Zinc-Ion Batteries

Abstract

Conventional zinc-ion batteries (ZIBs) are severely hindered by the inherent drawbacks of Zn metal anodes including dendrite growth, side reactions, and interface passivation. Developing intercalation-type anodes to fabricate rocking-chair ZIBs is a promising approach to overcome the above issues. However, the low capacity resulting from the limited transfer electron number of intercalation reactions impedes their practical applications. Herein, we report an effective strategy to break the capacity limit of layered CuS materials as a Zn-metal-free anode through activating its intrinsic conversion reaction. It is found that the preintercalation of cetyltrimethylammonium bromide in CuS (CuS@ CTMAB) significantly lowers the energy barrier of the conversion reaction, thus realizing a record-breaking capacity (367.4 mAh g −1 at 0.1 A g −1 ) as a Zn-metal-free anode based on the reversible conversion of Cu 2+ /Cu 0 . Theoretical calculation, ex situ microscopy, and spectroscopy results verify that the characteristic stepwise intercalation−conversion reaction route occurred in CuS@CTMAB. Moreover, the moderate structure transformation and good electronic conduction during the phase evolution process led to excellent cycling stability and high rate performance. Consequently, the rocking-chair ZIB full battery system utilizing CuS@CTMAB and Zn 2+preintercalated MnO 2 as the anode and cathode, respectively, exhibits exceptional capacity retention of 93.9% up to 8000 cycles at 2 A g −1 . Besides, the CuS@CTMAB anode is also compatible with high-voltage Prussian blue cathodes, demonstrating its outstanding practicality.

Synergistic Engineering of Sulfur Vacancies and Heterointerfaces in Copper Sulfide Anodes for Aqueous Zn‐Ion Batteries with Fast Diffusion Kinetics and an Ultralong Lifespan

“…Cu-based chalcogenides have attracted overwhelming attention as anode materials owing to their open framework, lower intercalation potential (vs Zn 2+ /Zn), and environmental benefits. [22][23][24][25] However, trapped in sluggish Zn 2+ migration dynamics and insufficient reactions caused by the strong electrostatic interactions between multivalent Zn 2+ and the host material, [26,27] it is difficult to perform a stable Zn 2+ accommodation reaction in Cu-based chalcogenide anodes. As previously reported, Ren.…”

Practical conversion-type titanium telluride anodes for high-capacity long-lifespan rechargeable aqueous zinc batteries

“…3f, the proposed TiTe 2 electrode has a high capacity and long cycling life among the state-of-the-art low-voltage electrodes for RAZBs. 23,25–29,38–40…”

“…3f, the proposed TiTe 2 electrode has a high capacity and long cycling life among the state-of-the-art low-voltage electrodes for RAZBs. 23,[25][26][27][28][29][38][39][40] The galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS) were carried out to probe the kinetic process. As shown in Fig.…”

“…6d, the TiTe 2 kZn x Co 3 O 4 battery presents a remarkable energy density of 149 W h kg À1 on the electrode level, surpassing the reported aqueous metal-free zinc full cells. 25,[27][28][29]38,39,[48][49][50][51][52] Fig. S10 † illustrates the rate capability of the TiTe 2 kZn x Co 3 O 4 pouch cell.…”

A strategy for anode modification for future zinc-based battery application

“…Although there is no example of a full-battery study of VS 2 as an anode, VS 2 as a zinc-metal-free anode offers a significant potential choice for non-aqueous ''rocking chair'' ZIBs. Similarly, CuS 124 as a Zn-metal-free anode for ''rocking chair'' ZIBs also has a two-step Zn 2+ storage process, combining both intercalation and conversion reactions (Fig. 13b), which could be summarized as follows: intercalation:…”