Lithium metal batteries have lithium anodes where they store their energy. Scientists at Tsinghua Shenzhen International Graduate School, and Shenzhen Institute of Advanced Technology have identified failure paths in lithium metal batteries, that predict subsequent performance. These ‘fingerprints’ also indicate which type of anode failure is likely.
Detecting Lithium Metal Anode Failure Paths
The scientists from Shenzhen City, which borders on Hong Kong to the south, wanted to understand lithium metal batteries better. They were particularly interested in their lithium anodes, which affect battery stability in storage applications.
The information that came to hand was all post-failure evidence. This therefore did not include the progressive stages leading to lithium metal battery failure, and so those cause-and-effect relationships remained somewhat a mystery.
We append a link to their research report in Oxford Academic below. This record describes how the Shenzhen City scientists first turned to artificial intelligence, to unravel a mountain of data. Their computer delivered a database of over 18,000 cycles, and 12 million data points from cells, which had cycled to failure.
This information revealed a correlation between initial lithium plating and stripping, and subsequent anode inconsistency. This data enabled the scientists to predict different failure paths in lithium metal anodes, after just two battery charge-discharge cycles.
The Key Electrochemical Fingerprints
The Shenzhen City researchers discovered what they called key electrochemical fingerprints, that predicted lithium metal battery anode degradation:
- First, the fingerprints described the lithium anode composition, and its interface layer leading to the electrolyte.
- And secondly, the fingerprints also had a bearing on the formation of ‘ineffective areas of that interface layer’.
- These inconsistent areas of the interface layer, made ineffective contact with the lithium metal battery anode.
- This in turn lengthened the distance that the lithium ions and electrons had to travel to and from the cathode.
- The net result of the inconsistent interface layer, was therefore less effective battery charging and discharging.
This new, validated model could enable battery developers to assess the future of their prototype lithium metal batteries within days, instead of waiting weeks, even months for new designs to degrade to failure.
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