Microbe-Assisted Nanocomposite Anodes for Aqueous Li-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Biomaterials Engineering

Background:

• Lithium-ion batteries (LIBs) face safety challenges due to flammable organic electrolytes.
• Water-in-salt (WIS) electrolytes offer a safer alternative but are limited by a high cathodic limit, restricting low-potential anode use.
• Developing effective interlayers is crucial for advancing WIS electrolyte technology.

Purpose of the Study:

• To synthesize biodirected carbonaceous interlayers for anodes in WIS electrolytes.
• To investigate the impact of microbe-derived carbon on anode conductivity and WIS electrolyte stability.
• To optimize microbe size and aspect ratio for enhanced battery performance.

Main Methods:

• Biodirected synthesis of carbonaceous layers using high-aspect ratio microbes on TiO2 nanoparticles.
• Utilizing microbes of varying aspect ratios to study network formation and battery performance.
• Performing density functional theory (DFT) calculations to elucidate the mechanism of performance improvement.
• Analyzing the effect of storage time on microbe size.

Main Results:

• Microbe-derived carbon interlayers (m-TiO2) significantly enhanced anode performance in WIS electrolytes.
• m-TiO2 anodes showed a 49% higher capacity at the 40th cycle compared to uncoated TiO2.
• The developed interlayers improved cycle life while using less carbon precursor than conventional methods.
• DFT calculations indicated that pyridinic nitrogen in microbe-derived carbon slows water diffusion.

Conclusions:

• Biodirected synthesis of carbonaceous interlayers using microbes is a viable strategy for safer and more efficient WIS electrolytes.
• Optimized microbe size and composition are key for maximizing battery performance.
• This approach offers a novel pathway for fabricating advanced energy storage materials from biomaterials.