Researchers from the Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) of the Chinese Academy of Sciences have made a breakthrough in defect engineering and performance improvement of all-solid-state lithium-sulfur batteries.
They used porous-carbon nanotubes (P-CNTs) as sulfur-bearing matrix, forming carbon based composite cathodes for the batteries.
P-CNTs acted as a mediator and established a stable triple phase between sulfur, P-CNTs, and ionic conductor solid-state electrolyte (SSE) Li6PS5Cl.
According to the study, the reaction activity and stability of the sulfur cathode in the battery could be substantially improved by optimizing the ion and electron transport networks.
The solid-state electrolyte can provide good charging and discharging performance for batteries even under -40°C.
“The capacity of soft pack all-solid-state batteries using this electrolyte can maintain 82.7% capacity after cycling 3,000 times at 25°C and 0.5°C, which initially solves the life-span problem of sulfide all-solid-state batteries,” according to the study published in ACS Applied Materials & Interfaces.
All-solid-state lithium–sulfur batteries are considered one of the most promising energy storage devices for high energy density, high safety, and low cost of sulfur.
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The technology replaces the liquid electrolyte with a solid one and uses lithium at the anode instead of graphite.
The solid-state batteries could grow to over $6 billion by 2030, according to a report by IDTechEx.
The technology, however, remains expensive and difficult to produce.
“Our work provides a new strategy for the microstructural engineering of carbon materials and interfacial modification for high-performance all-solid-state lithium-sulfur batteries,” said professor Wu Jianfei from the Qingdao Institute.