All solid-state batteries used diverse composites of different materials in their cathodes, in an attempt to improve ion conductivity. However, this approach can become dysfunctional, as layered cathode structures expand and contract during charging and discharging. Researchers at Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) in Shandong, China decided to use a zero-strain material instead.
Why Use a Zero Strain Material for Homogenized Cathodes?
Zero-strain battery materials show nil expansion and contraction during charging and discharging. Interesting Engineering confirms the benefits of this approach as follows:
- Zero-strain battery materials have mixed ionic and electrical conductivity.
- This facilitates efficient charge transfer during charging and discharging.
- And as a result, the homogenized cathodes do not require special additives.
Our new method of homogenizing the cathode goes against traditional heterogeneous cathodes, a team member remarks. Yet surprisingly, when we do away with those neutral additives, the energy density and battery life actually improve.
Could This Be a Candidate for Replacing Lithium-Ion?
Lithium-ion technology is surely a candidate for replacement, as it peaks in energy density and cycling life. Therefore, we need a new generation of batteries that make storing renewable energy cheaper, and electric vehicles travel further on a single charge.
The team from Qingdao Institute of Bioenergy and Bioprocess Technology base their claim on intensive testing. They report their batteries with homogenized cathodes have a specific capacity of 250 mAh per gram. While standard lithium-ion batteries only achieve 100-200 mAh per gram.
This novel way of thinking could be a game-changer for all-solid-state lithium batteries. Teaming high energy density with extended cycle life opens up new possibilities. This includes, interestingly enough, future high energy storage batteries using a variety of chemistries.
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Preview Image: Heterogeneous and Homogeneous Cathodes