Nanoscale Wrinkled Cu as a Current Collector for High-Loading Graphite Anode in Solid-State Lithium Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Solid-state lithium batteries are researched for enhanced safety and stability in energy storage.
• Current limitations include poor reversible capacity due to high internal resistance.
• Copper (Cu) current collectors are essential components in battery design.

Purpose of the Study:

• To improve the reversible capacity of solid-state lithium batteries.
• To reduce internal resistance by modifying the copper current collector surface.
• To investigate the effect of graphene and wrinkle structures on battery performance.

Main Methods:

• A graphene and wrinkle structure was synthesized on the copper current collector surface using chemical vapor deposition (CVD).
• The modified current collector was integrated with a graphite composite electrode.
• Electrochemical performance was evaluated using a solid polymer electrolyte.

Main Results:

• The modified graphene/wrinkled Cu current collector exhibited a periodic wrinkled pattern (420 nm width, 22 nm depth).
• An improved areal loading of approximately 2.5 mg cm^-2 was achieved.
• A significant increase in discharge capacity to 347 mAh g^-1 at 0.2 C was observed.
• Enhanced adhesion between the graphite anode and Cu current collector was confirmed via peel tests, attributed to mechanical interlocking.

Conclusions:

• The surface-modified Cu current collector effectively reduces resistance by improving anode adhesion, leading to enhanced solid-state lithium battery performance.
• Electrode design, specifically surface modification of current collectors, is crucial for improving battery capacity and efficiency.
• This approach offers a promising strategy for developing next-generation high-performance solid-state batteries.