A stable and ultrafast K ion storage anode based on phase-engineered MoSe₂.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Potassium-ion batteries (PIBs) offer a sustainable energy storage alternative due to potassium's abundance.
• Anode materials with sluggish kinetics and poor cycling stability currently limit PIB performance.

Purpose of the Study:

• To develop a high-performance anode material for PIBs.
• To address the challenges of slow kinetics and poor cycling stability in existing PIB anodes.

Main Methods:

• Synthesis of a hybrid 1T/2H phase MoSe2 anode material.
• Electrochemical characterization of the MoSe2 anode in PIBs, including cyclic voltammetry, galvanostatic charge-discharge, and rate capability tests.

Main Results:

• The hybrid 1T/2H phase MoSe2 anode demonstrated a noticeable pseudocapacitive response and fast kinetics for potassium storage.
• Achieved a high reversible capacity of 440 mA h g-1 after 100 cycles at 0.1 A g-1.
• Exhibited excellent rate capability with a capacity of 211 mA h g-1 at 20.0 A g-1.

Conclusions:

• The hybrid 1T/2H phase MoSe2 anode shows significant potential for high-performance potassium-ion batteries.
• Phase engineering of transition metal compounds is a promising strategy for developing advanced anodes for rapid-charging PIBs.