Enabling Durable and High-Energy Aqueous Proton Batteries by Engineering a Robust Polymer-Metal Complex Interphase on...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous proton batteries (APBs) offer a low-cost, safe alternative for energy storage.
• Current MnO2 cathodes suffer from low efficiency and capacity due to dissolution-deposition mechanisms in acidic electrolytes.

Purpose of the Study:

• To develop a novel Mn-based cathode material for APBs with improved performance.
• To address the dissolution and capacity decay issues of Mn-based cathodes.
• To elucidate the energy storage mechanism of Mn2O3 in acidic electrolytes.

Main Methods:

• Synthesized Mn2O3 as a cathode material.
• Engineered an in situ polymer-metal complex interphase (C-PMn) using polyacrylonitrile (PAN) and manganese triflate (Mn(OTf)2).
• Investigated the electrochemical performance and cycling stability of the modified Mn2O3 cathode in a proton battery.

Main Results:

• The C-PMn interphase effectively inhibited Mn2+ dissolution and enhanced proton permeability.
• The Mn2O3 cathode demonstrated a proton insertion/extraction mechanism, achieving high redox potential and specific capacity.
• A full battery (HATN//Mn2O3) exhibited 82% capacity retention after 500 cycles and an energy density of 115 Wh kg-1.

Conclusions:

• The engineered Mn2O3 cathode with a C-PMn interphase offers a promising solution for high-energy-density proton batteries.
• This approach provides a cost-effective strategy for optimizing cathode performance in acidic electrolytes.
• The findings pave the way for durable and high-performance aqueous proton battery development.