A Proton-Intercalation Pathway Realizes Long-Life Manganese-Ion Hybrid Batteries With Layered KV₃O₈

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous manganese-ion batteries (AMIBs) are crucial for large-scale energy storage due to their low cost and high safety.
• Developing high-performance cathode materials is essential for the commercialization of AMIBs.

Purpose of the Study:

• To introduce and evaluate monoclinic KV3O8 as a novel cathode material for AMIBs.
• To investigate the charge storage mechanism and structural properties of KV3O8 in AMIBs.

Main Methods:

• Electrochemical testing for cycling stability and rate capability.
• Advanced characterization techniques including XPS, EXAFS, XRD, FTIR, and Raman spectroscopy.
• Computational analysis of diffusion paths and energy barriers.

Main Results:

• Monoclinic KV3O8 exhibits a layered structure with a 7.63 Å interlayer spacing, enabling efficient ion intercalation.
• The material demonstrates excellent long-term cycling stability (88.0% retention after 3600 cycles) and superior rate performance.
• Both Mn2+ ions and protons were identified as charge carriers, with protons playing a predominant role.

Conclusions:

• Monoclinic KV3O8 is a highly stable and effective cathode material for AMIBs.
• The findings offer critical insights for designing advanced manganese-based cathode materials.
• This research marks a significant advancement toward the practical application of AMIBs.