Preparation of Single-Crystal Li-Rich Mn-Based Layered Oxides with Excellent Electrochemical Performance via Simple...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Li-rich Mn-based layered oxides are promising cathode materials for lithium-ion batteries due to high capacity, wide voltage, and low cost.
• Large-scale production of single-crystal Li-rich Mn-based layered oxides is challenging, hindering industrial application.

Purpose of the Study:

• To investigate methods for preparing single-crystal Li-rich Mn-based layered oxides.
• To evaluate the electrochemical performance of these materials.
• To develop a scalable and industrially viable synthesis route.

Main Methods:

• Comparison of solid-state and molten-salt flux methods for synthesis.
• Assessment of potassium chloride (KCl) as a fluxing agent.
• Development of a simple stepwise sintering process with water washing and annealing.

Main Results:

• Potassium chloride (KCl) enabled single-crystal formation but resulted in inferior electrochemical performance.
• Molten-salt flux method proved too complex for industrial scalability.
• Stepwise sintering yielded single-crystal Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ (536 nm) with 274.9 mAh·g^-1 capacity, 77.4% initial Coulombic efficiency, and 82.1% retention after 100 cycles at 0.1 C.

Conclusions:

• Water washing and annealing significantly enhance cycling performance.
• Simple stepwise sintering offers a viable route for industrial production of high-performance single-crystal Li-rich Mn-based layered oxides.
• This study provides theoretical guidance for scalable synthesis of advanced cathode materials.