Lithium-Ion Battery Testing Capable of Simulating “Ultralow” Lunar Temperatures

Abstract

The first-ever lithium-ion battery cycler capable of testing the coin and pouch cells under ultralow (≤40 °C) temperatures down to −175 °C to simulate extreme climates found in the lunar and space missions, high-altitude air vehicles, polar regions of Earth, and military expeditionary missions is enthusiastically reported. The extremely cold temperatures are achieved through a tailored extreme low-temperature system (ELTS) with liquid nitrogen flow and the ability to reach temperatures between −175 and 25 °C, using 1 kΩ and 1 MΩ resistors at varying currents of 1–4 mA and 1–4 μA, respectively, is validated. Employing the ELTS, Li4Ti5O12 (LTO)||Li cells with 1 m lithium bis(fluorosulfonyl)imide in cyclopentyl methyl ether as an electrolyte developed in this research group are charged and discharged at room temperature (cycling rate C/5), −20 (C/10), −40 (C/40), and −60 °C (C/50), which exhibited discharge capacities of 159.04, 119.12, 101.79, and 33.06 mAh g−1, respectively. Moreover, the LTO||Li cell produced a reversible capacity of 7.12 mAh g−1 tested at −100 °C for the first time.