A recent study in Small introduces a hyperstable aqueous zinc-ion battery (AZIB) using Mo1.74CTz MXene as the cathode material. This breakthrough offers significant performance improvements and long-term stability, making it ideal for applications like microgrids and backup power in remote areas.
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Background
The demand for sustainable energy storage solutions has intensified as conventional lithium-ion batteries (LIBs) face challenges such as resource scarcity, high costs, and safety concerns.
Aqueous zinc-ion batteries (AZIBs) present a promising alternative, using zinc’s abundance and low toxicity while ensuring enhanced safety. However, the main challenge in AZIBs is developing cathode materials that can efficiently accommodate divalent Zn2+ ions.
Two-dimensional (2D) materials like MXenes have emerged as strong candidates due to their layered structures, which allow for tunable interlayer spacing to facilitate ion intercalation.
The Current Study
The Mo1.74CTz MXene was synthesized by selectively etching (Mo0.87Cr0.13)2Ga2C in hydrofluoric acid, producing a stable MXene suspension. Following the etching process, an intercalation procedure was performed using TBAOH (tetrabutylammonium hydroxide) to enhance the exfoliation of MXene sheets. These sheets were then filtered and dried to form cathode films.
Electrochemical performance was assessed using galvanostatic charge/discharge, cyclic voltammetry (CV), and galvanostatic intermittent titration technique (GITT). These tests provided insights into capacity, coulombic efficiency, and cycling stability under varying current densities.
Results and Discussion
The Mo1.74CTz MXene-based zinc-ion batteries exhibited outstanding electrochemical performance, achieving a specific discharge capacity of 200 mAh g⁻¹ at 0.2 A g⁻¹—surpassing previously reported MXene-based AZIBs. The battery retained 75 % of its capacity after 100,000 cycles with nearly 100 % coulombic efficiency, indicating minimal degradation.
This stability is attributed to Mo1.74CTz’s layered structure and vertical holes, which prevent structural collapse during cycling. Charge/discharge curves showed high reversibility of zinc-ion intercalation and de-intercalation, with symmetrical galvanostatic discharge curves confirming excellent electrochemical stability. These results demonstrate that Mo1.74CTz MXene offers a high-capacity, long-life alternative to conventional AZIB cathode materials.
This work advances environmentally friendly battery technologies, addressing the growing demand for efficient energy storage. Its success could drive broader adoption and commercialization, shaping the future of sustainable energy solutions.
Journal Reference
Chen N., et al. (2025). A hyperstable aqueous zinc-ion battery based on Mo1.74CTz MXene. Small. DOI: 10.1002/smll.202409122, https://onlinelibrary.wiley.com/doi/10.1002/smll.202409122