Electrospinning Equipment: Cu-Sn Alloy Nanoparticles Modified Carbon Nanofibers for Dendrite-Free Zinc Ion Batteries

Aqueous zinc ion batteries (ZIBs) are currently highly promising rechargeable batteries, featuring affordable prices and high reliability. However, the uncontrolled growth of zinc dendrites, hydrogen evolution reactions, and side reactions severely limit their sustainable applications. The research team led by Professor Ji Liang from the School of Materials Science and Engineering at Tianjin University published the latest research findings titled "Cu-Sn Alloy Nanoparticles Modified Carbon Nanofibers for Dendrite-Free Zinc Ion Batteries" in the journal Journal of Energy Chemistry. The team successfully prepared Cu-Sn alloy nanoparticle-modified carbon nanofibers through electrospinning machine and high-temperature carbonization techniques, providing an innovative strategy for stabilizing the anode of zinc ion batteries and holding promise for promoting the widespread application of aqueous zinc ion batteries.

The research team dissolved copper salts, tin salts, and polyvinylpyrrolidone (PVP) in dimethylformamide (DMF), formed precursor fibers via electrospinning device and then carried out high-temperature carbonization treatment in an atmosphere of hydrogen and argon. Finally, Cu-Sn alloy nanoparticle-modified carbon nanofibers were obtained (Figure 1a). High-resolution transmission electron microscope (HRTEM) images show that Cu-Sn alloy nanoparticles are uniformly distributed in the carbon nanofibers (Figure 1d).

The Cu-Sn alloy nanoparticle-modified carbon nanofibers (Cu/Sn-C) obtained through electrospinning machine and high-temperature carbonization treatment possess a three-dimensional carbon network structure with high conductivity. The uniformly dispersed Cu/Sn-C has a high density of zincophilic sites, which can homogenize the zinc deposition behavior, reduce the risk of zinc dendrites penetrating the separator, and mitigate corrosion and side reactions (Figure 2). Calculations indicate that the adsorption energy of Zn²⁺ on the Cu₃Sn (002) substrate is -1.52 eV, showing a stronger binding affinity than carbon and pure Zn, suggesting the strongest electronic interaction and interfacial polarization between Cu₃Sn and Zn atoms (Figure 4).

The symmetric cell with a Cu/Sn-C@Zn anode exhibits a cycling lifespan of over 3500 hours at 1 mA cm⁻² and a capacity of 1 mAh cm⁻², demonstrating excellent rate performance. Even at a high current density of 5 mA cm⁻², it can achieve a long cycling lifespan of 1500 hours, and shows a low overpotential and excellent rate performance at different current densities (Figure 5).

The Cu/Sn-C@Zn//MnₓV₂O₅ full battery achieved stable cycling at 5 A g⁻¹. After 1000 cycles, the Cu/Sn-C@Zn//MVO battery achieved a higher reversible capacity compared to the CNFs@Zn//MVO full battery, demonstrating better cycling stability and rate performance (Figure 6).

In conclusion, the authors successfully prepared Cu/Sn-C rich in zincophilic sites as a buffer interface region (BIR) to stabilize the zinc anode via the electrospinning device method. It was found that the high-density dispersed Cu-Sn alloy has a high zinc affinity, which can regulate the zinc deposition process to inhibit the formation of zinc dendrites and suppress side reactions, thereby extending the cycle life. The Cu/Sn-C@Zn symmetric cell exhibited a long cycling lifespan of 3500 hours at 1 mA cm⁻² and excellent rate performance. After 1000 cycles, the Cu/Sn-C@Zn//MVO battery achieved a higher reversible capacity compared to the CNFs@Zn//MVO full battery. This study proposes an innovative method for stabilizing zinc ion anodes, paving the way for the widespread application of aqueous zinc ion batteries (AZIBs).

Article source: https://doi.org/10.1002/batt.202500205