A Core-shell Electrode Configuration for Lithium-Sulfur Battery and Methods of Making the Same

Physical Sciences : Materials and Compounds

Available for licensing

Inventors

  • Arumugam Manthiram, Ph.D. , Mechanical Engineering
  • Sheng-Heng Chung , University of Texas at Austin

Background/unmet need

Sulfur is an appealing cathode material for establishing advanced lithium batteries, as it offers a high theoretical capacity of 1675 mAh g-1 with low material and operating costs. However, the lithium-sulfur (Li-S) electrochemical cells face several formidable challenges arising from both the materials chemistry (e.g., low electrochemical utilization of sulfur and severe polysulfide diffusion) and battery chemistry (e.g., dynamic and static instability and low sulfur loadings).

Also, the conventional cathode configuration may not be able to make the best use of sulfur because of the differences in the battery chemistries between the lithium-insertion-compound oxide cathodes and the conversion-reaction sulfur cathodes. Lastly, the cyclability of Li-S cells faces a significant decline on going from low sulfur loadings (less than 2 mg/cm2) to high sulfur loadings.

Invention Description

Researchers at The University of Texas at Austin have presented the design of a core-shell cathode with a pure sulfur core shielded within a conductive shell-shaped electrode. The new electrode configuration allows Li-S cells to load with a high amount of sulfur (sulfur loadings of up to 30 mg cm2 and sulfur content approaching 70 wt%). The core-shell cathodes demonstrate a superior dynamic and static electrochemical stability in Li-S cells. The high-loading cathodes exhibit a high sulfur utilization of up to 97% at C/20 ? C/2 rates and exhibit low self-discharge during long-term cell storage for a three-month rest period. Finally, a polysulfide-trap cell configuration is designed to evidence the eliminations of polysulfide diffusion.

Benefits/Advantages

  •  Excellent cell performance
  • High practicality
  • Outstanding feasibility

Features

  • Core-shell cathodes encapsulate an increasing amount of active material up to 30 mg/cm2.
  • High loading sulfur core exhibits high electrochemical utilization, stable cyclability, and good rate capability.
  • Good balance between performance and real feasibility.
  • Core-shell cathodes stabilize their high loading sulfur core during cell resting.

Market potential/applications

Companies involved with lithium batteries, lithium-ion batteries, lithium-sulfur batteries, and electrochemical energy storage systems for grid energy storage

Development Stage

Lab/bench prototype