Tetrahedral Lithium Stuffing in Disordered Rocksalt Cathodes for High-Power-Density and Energy-Density Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Li-rich cation-disordered rocksalt (DRX) materials offer high capacity for Li-ion batteries.
• DRX materials suffer from slow kinetics and poor rate performance due to random Li diffusion.

Purpose of the Study:

• To engineer a novel Li diffusion pathway in Mn-based DRX materials.
• To improve the rate capability and cycling stability of DRX cathode materials.

Main Methods:

• Computational modeling and experimental synthesis of Li-stuffed DRX materials.
• Electrochemical testing to evaluate energy density and rate performance.
• Structural analysis to confirm Li site occupancy and stability.

Main Results:

• Tetrahedral Li stuffing creates a tetrahedron-octahedron-tetrahedron diffusion pathway with a low energy barrier.
• Enhanced lattice oxygen and suppressed transition metal migration improve cycling stability.
• Achieved high energy density (311 mAh g⁻¹, 923 Wh kg⁻¹) and power density (251 mAh g⁻¹, 697 Wh kg⁻¹ at 1000 mA g⁻¹).

Conclusions:

• Li stuffing in DRX materials significantly enhances Li-ion transport and electrochemical performance.
• This strategy offers a promising route for developing high-performance, earth-abundant cathode materials.
• The findings open new avenues for designing advanced Li-ion batteries based on rocksalt structures.