Self-Regulatory Lean-Electrolyte Flow for Building 600 Wh Kg^-1-Level Rechargeable Lithium Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Reducing electrolyte content is key for higher energy density in storage devices.
• Porous electrode materials face challenges with uneven wetting in lean electrolytes.
• Internal pore wetting can negatively impact performance under these conditions.

Purpose of the Study:

• To mitigate heterogeneous wetting in porous electrodes under lean electrolyte conditions.
• To enhance the performance of Li-rich layered oxides at low electrolyte/capacity ratios.
• To explore the relationship between pore structure and electrolyte permeability.

Main Methods:

• Enlarging the pore-throat ratio in electrode materials.
• Utilizing Li-rich layered oxide as the electrode material.
• Conducting experiments at a low electrolyte/capacity (E/C) ratio of 1.4 g Ah⁻¹.
• Employing imaging techniques and molecular dynamics simulations.

Main Results:

• Achieved a pouch cell specific energy of 606 Wh kg⁻¹.
• Retained 80% capacity and 75% energy after 70 cycles.
• Demonstrated that pore-throat ratio dictates electrolyte permeability within particles.

Conclusions:

• Enlarging the pore-throat ratio effectively addresses wetting issues in lean electrolytes.
• This strategy enables high performance for Li-rich layered oxides at low E/C ratios.
• Manipulating pore structures offers a viable approach for improving energy storage devices, including semi-solid-state lithium batteries.