Rechargeable alkaline Zn-Cu batteries enabled by carbon coated Cu/Bi particles

In this work, we demonstrate using Cu as the cathode active material in alkaline Zn batteries by forming nanoscale carbon coated Cu/Bi particles through the carbonization of dopamine coated CuO/Bi2O3. The resulting particles were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), elemental analysis (EA), and Raman spectroscopy. The carbon coating was found to be roughly 20 nm thick with a mass loading of similar to 8 wt%. When cycled versus pasted Zn anodes, the Cu/Bi@C cathodes provided 200 cycles at similar to 300 mAh/g and similar to 100 Wh/L. SEM, EDS, XRD, and optical images were used to track changes in the electrode structure and morphology over the first 50 cycles. Solubility of Cu and Bi species was found to decrease the capacity during the first 10 cycles, followed by minimal losses thereafter. The carbon coating enables consistent cycling performance and prevents the formation of detrimental Cu2O structures found in passivated Zn/CuO batteries. This work exemplifies the benefits of nanoscale carbon coatings for Cu particles providing further insight into methods for realizing a Cu based cathode for rechargeable alkaline Zn batteries.

Automated summary

This work demonstrates the utilization of Cu as the cathode active material in alkaline Zn batteries through the formation of nanoscale carbon-coated Cu/Bi particles. The carbon coating provides consistent cycling performance and prevents the formation of detrimental Cu2O structures. Various characterization techniques were used to analyze the properties of the resulting particles. This study provides further insight into methods for realizing a Cu-based cathode for rechargeable alkaline Zn batteries.