Synergistic Dual-Pinning Engineering Enables Stable Mn-Based Layered Oxide Cathodes for High-Performance Sodium-Ion Batteries.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40864667.
- Also identified by DOI 10.1021/acsnano.5c11703.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Mn-based oxide cathodes for sodium-ion batteries (SIBs) often suffer from structural degradation caused by Jahn-Teller distortion and irreversible phase transitions. Here, we propose a dual-site stabilization strategy by Mo/Mg codoping, which not only drives the transformation of the tunnel-type Na<sub>0.44</sub>MnO<sub>2</sub> into a P2-layered structure (Na<sub>0.44</sub>Mn<sub>0.97</sub>Mo<sub>0.01</sub>Mg<sub>0.02</sub>O<sub>2</sub>, denoted as MoMg-12) by modulating the total energy to enhance capacity but also employs Mo and Mg ions substituting Mn sites to implement synergistic dual-pinning engineering to stabilize the structure. This dual-pinning mechanism concurrently suppresses Jahn-Teller distortion by stabilizing Mn redox activity and improves air stability by reducing Na<sup>+</sup>/H<sup>+</sup> exchange while promoting a hydrophobic surface. The optimized MoMg-12 cathode delivers a high specific capacity of 189 mAh g<sup>-1</sup> within its stable P2-type layered structure coupled with superior rate capability and long-term cycling stability. In addition, its practical viability is demonstrated when paired with a Na<sub>2</sub>C<sub>2</sub>O<sub>4</sub> sodium compensation additive. This study highlights the effectiveness of the dual-pinning engineering in preserving structural integrity and offers a practical design example for high-energy-density and air-stable SIB cathodes.