Lithium diffusion-controlled Li-Al alloy negative electrode for all-solid-state battery.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41173889.
- Also identified by DOI 10.1038/s41467-025-64386-y and PMC identifier 12579251.
- 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
Metal alloy negative electrodes are promising candidates for lithium all-solid-state batteries due to their high specific capacity and low cost. However, chemo-mechanical degradation and atomic transport limitations in the solid state remain unresolved challenges. Herein, we demonstrate a lithium-aluminum alloy negative electrode design (Li<sub>x</sub>Al<sub>1</sub>, x = molar ratio of lithium to aluminum) based on a comprehensive understanding of the underlying diffusion mechanisms within the lithium-poor α (0 ≤ x ≤ 0.05) and lithium-rich β phases (0.95 ≤ x ≤ 1). The lithium-aluminum alloy negative electrodes with a higher lithium to aluminum ratio facilitate lithium migration through the β-LiAl phases, which serve as highly lithium-conductive channels with a lithium diffusion coefficient that is ten orders of magnitude higher than that of the α phase. In addition, a bulk dense negative electrode and an intimate negative electrode-electrolyte interface is demonstrated in the cross-sections of the lithium-aluminum alloy negative electrodes. Consequently, a high-rate capability of 7 mA cm<sup>-2</sup> is attained in LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub>-based full-cell operation. The optimal cell configuration of Li<sub>0.5</sub>Al<sub>1</sub> | |LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub> shows stable lithium reversibility during 2000 cycles with a capacity retention of 83% at 4 mA cm<sup>-2</sup> with a LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub> loading of 5 mAh cm<sup>-2</sup>.