A Biomimetic Polydimethylsiloxane Barrier in the Interface for Stable Potassium Metal Battery Anodes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Potassium metal batteries (KMBs) offer high theoretical energy density for energy storage.
• Dendrite growth on potassium anodes is a major challenge limiting KMB performance and safety.

Purpose of the Study:

• To design and evaluate a biomimetic protective interface for potassium metal anodes.
• To address dendrite formation and improve the stability of KMBs.

Main Methods:

• A polydimethylsiloxane (PDMS)-based interface was designed and applied to the potassium metal anode.
• Theoretical calculations and experimental validation were employed.
• Electrochemical performance was assessed using symmetric cells and full cells (K@PDMS//PTCDA).

Main Results:

• The PDMS interface effectively shielded potassium metal from side reactions.
• It promoted the formation of a stable solid electrolyte interphase (SEI) layer.
• K@PDMS symmetric cells demonstrated stable cycling for over 2700 hours.
• K@PDMS//PTCDA full cells retained 71% capacity after 500 cycles.

Conclusions:

• The biomimetic PDMS interface is a promising strategy for developing high-performance and stable KMB anodes.
• This approach enhances ion transport and uniform potassium deposition, mitigating dendrite issues.