Potassium Underpotential Deposition for Defect‐Free Lithium Deposition in Anode‐Free Li‐Metal Batteries

• DOI: 10.1002/smtd.202500207
• Publication Date: 2025-05-13T10:23:29Z
• Authors: Kassie Nigus Shitaw; Hailemariam Kassa...; Yosef Nikodimos; Misganaw Adigo Weret; Teshager Mekonnen...; Semaw Kebede Merso; Bereket Woldegbre...; Shi‐Kai Jiang; Chun‐Ying Li; Hsin‐Yueh Liu; She‐Huang Wu; We‐Nien Su; Bing Joe Hwang
• Keywords: Underpotential deposition; Bimetallic strip; Deposition

Abstract Defects in deposited lithium (Li) severely cause dendrite growth and promote reactions between Li electrolytes, resulting active loss anode‐free metal batteries (AFLMBs). Herein, potassium underpotential deposition (K‐UPD) is systematically established to heal defective create a K‐Cu bimetallic interface, facilitating uniform bulk deposition. The K‐UPD at potential of ≈1.0 V, higher than the equilibrium potentials K⁺ (0.1 V) Li⁺ (0.0 V), significantly lowers nucleation barrier mitigates due better lithiophilicity K compared Cu. Meanwhile, surface mobility atoms enables defects prevent electrolytes. lower adsorption energy (ΔE) (−1.56 eV) that (0.032 indicates favorable atom, as confirmed by DFT calculations. As result, Cu||Li cell containing 1.3 M LiFSI+0.2 KFSI electrolyte reaches >1600 h, while Cu||NMC532 full‐cell achieves average Coulombic efficiency (avg. CE) 99.6% with 1.5 LiFSI (≈98.2%) after 100 th cycle. This work offers insights into mechanism for enhancing interface stability healing Li.