An Energetic CuS-Cu Battery System Based on CuS Nanosheet Arrays

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous battery technologies are crucial for renewable energy but are limited by electrode material performance.
• Existing materials suffer from poor conductivity, low capacity, and inadequate cycling stability.

Purpose of the Study:

• To develop a low-cost, high-energy aqueous copper ion battery system.
• To overcome the limitations of current electrode materials for stationary energy applications.

Main Methods:

• Fabrication of energetic aqueous copper ion system using CuS nanosheet arrays.
• Electrochemical characterization including capacity, rate capability, and cycling stability tests.
• Investigation of charge-storage mechanism using ex situ and in situ techniques.

Main Results:

• Achieved a high capacity of 510 mAh g^-1 with CuS nanosheet arrays.
• Demonstrated robust rate capability (497 mAh g^-1 at 7.5 A g^-1) and ultrastable cycling (91% retention over 2500 cycles).
• Identified reversible transitions between CuS, Cu₇S₄, and Cu₂S via Cu²⁺/Cu⁺ redox.

Conclusions:

• The CuS nanosheet array system offers a promising solution for high-performance aqueous batteries.
• A hybrid ion battery (CuS positive, Zn negative) achieved 286 Wh kg^-1 energy and 900 W kg^-1 power.
• This technology surpasses many existing aqueous battery systems, advancing renewable energy storage.