High-energy anode-free Li metal batteries with in-built surface-fluorinated Li-rich Mn-based cathodes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Anode-free lithium metal batteries (AF-LMBs) offer high energy density but face challenges with low Coulombic efficiency and short cycle life.
• Surface-stabilized Li-rich Mn-based oxide (LRMO) cathodes possess high capacity and a Li replenishment effect.

Purpose of the Study:

• To enhance the energy density and cycle life of AF-LMBs.
• To utilize the irreversible capacity loss during LRMO formation for Li inventory compensation.
• To improve the cathode-electrolyte interphase and LRMO surface stability.

Main Methods:

• Employing surface-stabilized Li-rich Mn-based oxide (LRMO) cathodes in AF-LMBs.
• Harnessing irreversible capacity loss during LRMO formation for in-situ Li deposition.
• Utilizing a localized high-concentration electrolyte with hydrofluoroether cosolvents.

Main Results:

• A 2-Ah anode-free pouch cell demonstrated 80% capacity retention after 260 cycles.
• A 30-Ah pouch cell achieved 350 Wh/kg and 1200 Wh/L with 84.4% retention after 180 cycles.
• The batteries exhibited excellent low-temperature performance and rate capability.

Conclusions:

• The developed AF-LMBs show commercial viability for high-energy and long-life applications.
• Coherent design of cathode and electrolyte is crucial for advancing AF-LMB technology.
• The strategy effectively compensates for Li inventory loss and enhances battery stability.