Covalent Carbide Interconnects Enable Robust Interfaces and Thin SEI for Graphite Anode Stability under Extreme Fast...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Carbonaceous electrodes are widely used in energy storage but suffer from unstable electrical pathways due to conductive additives and binders.
• Developing electrodes with enhanced electrical and mechanical integrity is crucial for improving device performance and longevity.

Purpose of the Study:

• To present a general approach for fabricating robust electrodes with progressive failure mechanisms using carbide-based interconnects.
• To enhance both electrical and mechanical properties of electrodes for electrochemical energy storage.

Main Methods:

• Carbothermal conversion of titanium hydride nanoparticles to form carbide-based interconnects within the electrode architecture.
• Investigating the resulting chemical bonding between active materials to maintain stable electrical pathways.
• Fabricating and testing lithium-ion battery anodes with the novel electrode structure.

Main Results:

• Electrodes exhibited improved cyclability, retaining 80% capacity after 800 fast-charge cycles at moderate loading (1 mAh cm^-2).
• High loading cells (3 mAh cm^-2) showed significantly improved cycle life.
• Performance enhancement attributed to suppressed impedance growth and thinner solid electrolyte interphase (SEI) layer formation at high current densities (4C).

Conclusions:

• The carbothermal conversion method successfully creates robust electrodes with enhanced electrical and mechanical properties.
• The novel electrode design maintains stable electrical pathways, leading to improved cyclability and extended cycle life in lithium-ion batteries.
• Reduced impedance growth and optimized SEI formation are key factors in the enhanced battery performance.