Polypyrrole Interlayer Improves Lithium Sulfur Battery Technology
JUL 2 2014 BY MARK KANE
Scientists from CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics and Chinese Academy of Sciences recently presented another concept of increases durability for lithium-sulfur batteries, which despite high energy densities, have issues with low cycle numbers.
The new solution developed by the Chinese team maybe still does not bring ultimate performance to the table, but at least the results on the prototype level are promising.
“Polypyrrole functional interlayer is in-situ fabricated uniformly onto the surface of sulfur cathode to inhibit the dissolution of lithium polysulfides and protect sulfur cathode. Li–S battery with the functional inlayer shows an encouraging electrochemical performance. The initial discharge capacity is 719 mAh g−1 and the capacity retains at 846 mAh g−1 even after 200 cycles at 0.2C with an average coulombic efficiency of 94.2%. Moreover, the discharge capacities are 703 mAh g−1 and 533 mAh g−1 at 1C and 2C respectively even after 300 cycles.”
300 cycles at 1C and 2C (30-minute charge/discharge) is still a little bit too low for EVs (but a good starting point) and coulombic efficiency fell a few percent compared to lithium-ion batteries, but we are still not losing faith that one of the designs will eventually enable commercialization of Li-S with 2-3 times higher capacities than we have today in lithium-ion.
Categories: Battery Tech