Lithium-Lithium Titanate Composite Anode for Semi-Solid-State Lithium-Sulfur Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries offer high theoretical energy density due to sulfur's abundance and properties.
• Challenges include volume expansion, dendrite formation, and polysulfide shuttling, limiting cycle life.
• Solid-state electrolytes show promise but anode issues persist in Li-S solid-state batteries.

Purpose of the Study:

• To investigate the performance of a composite anode for lithium-sulfur batteries.
• To address interfacial resistance and volume expansion issues associated with lithium metal anodes.
• To compare a polyacrylonitrile sulfur (PANS) cathode with a lithium-lithium titanate (Li-LTO) composite anode against a pure lithium metal anode.

Main Methods:

• Fabrication and testing of a full Li-S cell utilizing a PANS cathode and a Li-LTO composite anode.
• Comparative analysis against a Li-S cell with a pure lithium metal anode.
• Electrochemical cycling at 0.2 C for over 150 cycles.

Main Results:

• The Li-LTO composite anode demonstrated improved discharge capacity retention over 150 cycles.
• The pure lithium-sulfur (Li-S) cell with a lithium metal anode lost all discharge capacity around 100 cycles.
• The composite anode effectively mitigated interfacial resistance and volume expansion issues.

Conclusions:

• The lithium-lithium titanate composite anode is a viable solution for enhancing the stability and cycle life of lithium-sulfur batteries.
• This composite anode strategy offers a promising pathway for next-generation high-energy-density batteries.
• Further exploration of composite anode materials is warranted for advanced Li-S battery development.