# Substrate Designs for Stable Potassium Metal Anodes

## TL;DR

This review discusses strategies to stabilize potassium metal anodes in batteries to improve their performance and safety.

## Contribution

The paper categorizes and evaluates five substrate design strategies for potassium metal anodes.

## Key findings

- Three-dimensional host architectures and heteroatom doping improve anode stability.
- Inorganic nanoparticles and alloying seeds help control potassium deposition.
- Work function modulation aids in forming stable solid electrolyte interphases.

## Abstract

Potassium metal batteries (PMBs) are gaining attention
as low-cost,
sustainable, and high-energy storage. Their practical implementation,
however, is impeded by instability of the potassium (K) metal anode,
manifested as dendritic growth, large volume fluctuations, and fragile
solid electrolyte interphases (SEIs), all of which accelerate capacity
fading and safety risks. This review highlights recent advances in
substrate design for stabilizing K metal anodes, categorized into
five strategies: (i) three-dimensional host architectures, (ii) heteroatom
doping and molecular grafting, (iii) inorganic nanoparticle incorporation,
(iv) alloying seed engineering, and (v) substrate-regulated SEI formation
via work function modulation. Mechanistic insights from experimental
and theoretical studies are integrated with performance comparisons
to evaluate trade-offs between deposition control, SEI stability,
scalability, and cost. Key challenges for commercialization are outlined,
including long-term cycling under practical conditions, integration
with high-energy-density cathodes, and scalable fabrication. By advancing
structural, chemical, and electronic design principles, PMBs can progress
toward reliable, high-performance energy storage.