Axially coordinated single-atom interface mitigates isolated K toward highly reversible anode-free K metal batteries.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 42497267.
- Also identified by DOI 10.1126/sciadv.aef1038 and PMC identifier 13398483.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Potassium (K) metal anodes suffer from uncontrolled solid electrolyte interphase evolution and isolated K accumulation, greatly hindering the construction of practical anode-free batteries. To date, systematic investigations on K stripping behavior and isolated K formation, despite being fundamentally important, are still lacking. Here, we develop an axially coordinated single-atom iron (Fe) anchored on hollow carbon bowls to synergize promoted K desorption and stress-adaptive ion transport. Serving as current collector modification, the FeN<sub>4</sub>O<sub>2</sub> moiety optimizes K adsorption/desorption strength, regulates FSI<sup>-</sup> decomposition, and suppresses electronically isolated K. Meanwhile, the mechanically compliant carbon-bowl scaffold mitigates volumetric strain during cycling, preserving interfacial integrity and accelerating desorption at the stripping frontier. Multimodal evidence from cryo-transmission electron microscopy, x-ray photoelectron spectroscopy depth profile, and theoretical calculations collectively reveals a bidirectional regulation to enhance both deposition uniformity and stripping reversibility. The anode-free K metal full cell delivers nearly 100 milliampere-hours per gram over 200 cycles at 200 milliamperes per gram, readily rivaling the state-of-the-art counterparts.