Engineering Moderately Lithiophilic Paper-Based Current Collectors with Variable Solid Electrolyte Interface Films...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Anode-free lithium metal batteries (ALMBs) offer high energy density and simplified manufacturing by using bare current collectors instead of lithium metal anodes.
• The current collector's properties critically influence lithium deposition/stripping and lithium depletion rates, impacting battery performance and longevity.
• Developing efficient and stable current collectors is key to realizing the full potential of ALMBs.

Purpose of the Study:

• To investigate the effect of current collector lithiophilicity on solid electrolyte interface (SEI) formation and cycling performance in ALMBs.
• To explore the use of lightweight, paper-based current collectors modified with copper (Cu) and silver (Ag) for ALMB applications.
• To correlate current collector properties with lithium distribution and depletion rates in different electrolytes.

Main Methods:

• Fabrication of paper-based current collectors (LDP@Cu, LDP@Cu-Ag, LDP@Ag) via electroless plating with controlled loadings of Cu and Ag.
• Tuning the lipophilicity of current collectors by varying the silver content.
• Investigating the impact of these collectors on SEI composition and lithium depletion rates using electrochemical cycling in common electrolytes.

Main Results:

• Paper-based current collectors (LDP@Cu, LDP@Cu-Ag, LDP@Ag) with areal densities of ~0.33 mg cm^-2 were successfully prepared.
• Increased lipophilicity (higher Ag loading) enhanced lithium deposition but accelerated lithium depletion from the cathode.
• Moderately lithiophilic collectors (LDP@Cu-Ag) demonstrated balanced lithium deposition/stripping and stable SEI formation with reduced lithium depletion.

Conclusions:

• Current collector lithiophilicity is a critical parameter for optimizing ALMB performance.
• Paper-based current collectors offer a lightweight and potentially scalable solution for ALMBs.
• Optimized lithiophilic current collectors, like LDP@Cu-Ag, are essential for achieving stable cycling and high energy density in anode-free lithium metal batteries.