Comparative Testing Study: Commercial 18650-Format Li-Ion

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LockH   100 GW

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Comparative Testing Study: Commercial 18650-Format Li-Ion

Post by LockH » Nov 15 2015 11:59pm

"A Comparative Testing Study of Commercial 18650-Format Lithium-Ion Battery Cells"

Only ONE mention of this study/report here on ES (that I could find), buried in one thread. Just hope to "kick it up a notch" maybe:
http://jes.ecsdl.org/content/162/8/A1592.full
Abstract

Demand for portable electronic and electrical devices has led to considerable growth in production of lithium-ion battery cells and the number of manufacturers thereof. However, due to lack of supplied information or independent verification, it is frequently difficult to compare cells based on available data. In this study, we conduct a comparative testing study on five types of 18650-format lithium-ion cells from three different commercial manufacturers, ranging from budget to high-performance cells. Key insights gathered in the comparison were that the tested budget cells frequently offer less than 20% of their rated capacity, that the budget cells degrade at a significantly higher proportional rate than other cells, and that certain high-performance cells exceed the size dimensions of the 18650-format by over 3%. Electrochemical impedance spectroscopy testing showed the budget cells to have internal impedances several times higher than other cells, leading to notably increased heat generation and a significantly reduced cell efficiency. Differential capacity analysis found this high internal resistance to notably impede lithium intercalation processes. The presented methodology is intended as a base framework for conducting subsequent comparative testing studies for Li-ion cells.
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Nobuo   10 kW

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Re: Comparative Testing Study: Commercial 18650-Format Li-Io

Post by Nobuo » Feb 20 2016 2:42am

All the data show what other tests use to make in conclusion. Budget batteries never worth, if you take into account the useful energy along its lifetime, you pay more for each Wh. Otherwise all the batteries wear more or less, but it doesn't show how different is the wearing at high rates (higher temp), and that's also important.

Nice documentation. Thank for sharing
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