Tailoring Synergistic Ion Environment for Copper Telluride toward High-Capacity and Ultrastable Acidic...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Developing stable, high-capacity electrodes for acidic batteries is crucial for reliable low-temperature energy supply.
• Existing electrode materials face challenges with lifespan and stability in corrosive acidic environments.

Purpose of the Study:

• To explore nonstoichiometric copper telluride (Cu_2-xTe) nanosheets as advanced electrodes for acidic batteries.
• To evaluate the electrochemical performance, stability, and lifespan of Cu_2-xTe in acidic battery systems.

Main Methods:

• Synthesis of nonstoichiometric copper telluride (Cu_2-xTe) nanosheets.
• Electrochemical characterization including cyclic voltammetry and galvanostatic charge-discharge.
• In situ synchrotron X-ray diffraction and X-ray absorption spectroscopy.
• First-principles calculations to understand reaction mechanisms.

Main Results:

• Cu_2-xTe electrodes exhibit a stable capacity of 409 mAh g^-1 and an exceptional lifespan of 40,000 cycles.
• The material demonstrates excellent kinetics, enabling operation at high current densities (20 A g^-1) and low temperatures (-20 °C).
• Copper ion and hydrogen ion enrichment in the electrolyte synergistically stabilize the Cu_2-xTe electrode, driving reversible multielectron transfer.

Conclusions:

• Nonstoichiometric copper telluride (Cu_2-xTe) nanosheets are highly promising electrode materials for advanced acidic batteries.
• The unique stabilization mechanism in acidic electrolytes overcomes previous limitations, enabling superior performance and longevity.
• Cu_2-xTe-based full cells demonstrate stable operation, paving the way for progress in low-temperature energy storage solutions.