https://www.futureelectronics.com/resources/featured-products/nichicon-slb-series-lto-battery . Nichicon (SLB) series are (Small Li-Ion Rechargeable Batteries) suitable for IoT and wearable applications which utilize lithium titanate (LTO) for the negative electrodes. They are capable of charging at a low rate using energy harvesting with low temperature characteristics enabling operation even at -30 ℃. 
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