Mechanochemical Transformation From Zigzag‐Type Layered/Phenakite to Disordered Rocksalt in Mn‐Rich Cathodes for Li‐Ion Batteries

Why It Matters

The breakthrough offers a cost‑effective, earth‑abundant cathode with markedly higher capacity and cycle life, accelerating the commercialization of next‑generation EV batteries.

Key Takeaways

• Mechanochemical activation converts Mo/F‑doped precursor to Mn‑rich DRX
• Resulting disordered rocksalt delivers 297.9 mAh g⁻¹ reversible capacity
• Cation mobility and structural reversibility improve cycling stability
• Mo and F co‑doping drives zigzag layered/phenakite formation
• Single‑phase Mn/O redox replaces two‑phase mechanism, enhancing efficiency

Pulse Analysis

Mn‑rich cathodes have long promised high energy density at low cost, yet their practical adoption has been hampered by structural instability and sluggish lithium transport. Disordered rocksalt (DRX) materials address these issues by randomizing cation sites, which creates three‑dimensional diffusion pathways. However, achieving controlled disorder without sacrificing capacity has remained a scientific hurdle. The new study leverages mechanochemical activation—a high‑energy milling process—to induce a precise structural transition, offering a fresh route to engineer DRX phases.

The researchers introduced molybdenum and fluorine into a Li1.2Mn(2+x)/3Mo(0.4‑x)/3O2‑xFx precursor. Mo acts as a stabilizing pillar while F expands the lattice, together fostering a zigzag‑type layered/phenakite mixed structure. Subsequent mechanochemical treatment triggers local reconstruction, collapsing the layered framework into a disordered rocksalt lattice. This transformation not only boosts cation mobility but also consolidates the redox chemistry into a single‑phase Mn/O process, eliminating the voltage fade typical of two‑phase systems and delivering a reversible capacity near 300 mAh g⁻¹.

From an industry perspective, the approach aligns with scalable, low‑temperature processing, reducing reliance on expensive cobalt and complex synthesis routes. The ability to tune disorder through dopant chemistry opens pathways to tailor performance for specific applications, from fast‑charging EVs to grid‑scale storage. As manufacturers seek to lower material costs while meeting stringent energy‑density targets, Mn‑rich DRX cathodes engineered via mechanochemical activation could become a cornerstone of next‑generation lithium‑ion technology.