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.

Enabling Extreme Low‐Temperature (≤ −100 °C) Battery Cycling with Niobium Tungsten Oxides Electrode and Tailored Electrolytes

“…The 1.0-CPME, which demonstrated repeated charge/discharge ability at −100 °C and has a melting point of −140 °C, could be an alternative for battery operations at further low temperatures. [20,26] With the 1.0-CPME electrolyte, a NbWO||Li cell finally achieved >75 mAh g −1 capacity at C/30, which is a significant improvement in −100 °C cell performance compared to the previous result of an Li 4 Ti 5 O 12 ||Li cell in the 1.0-CPME. [26] The differential capacity plots at different temperatures show that only Nb 5+ /Nb 4+ reaction peaks remain discernible at −80 and −100 °C throughout the charge and subsequent discharge (Figure S9, Supporting Information).…”

“…[20,26] With the 1.0-CPME electrolyte, a NbWO||Li cell finally achieved >75 mAh g −1 capacity at C/30, which is a significant improvement in −100 °C cell performance compared to the previous result of an Li 4 Ti 5 O 12 ||Li cell in the 1.0-CPME. [26] The differential capacity plots at different temperatures show that only Nb 5+ /Nb 4+ reaction peaks remain discernible at −80 and −100 °C throughout the charge and subsequent discharge (Figure S9, Supporting Information). This indicates that the capacitive Li + storage property demonstrated by the CV measurement becomes more prominent at lower temperatures, significantly influencing extreme low-temperature battery operations, while the diffusion-controlled intercalation reactions are greatly limited at such temperature regimes.…”

Tailored Solvation and Interface Structures by Tetrahydrofuran‐Derived Electrolyte Facilitates Ultralow Temperature Lithium Metal Battery Operations

“…The low temperature cell tests were performed on a customized cooling plate with liquid nitrogen cooling system (INSTEC HCP402SG-PM +). [24] Electrochemical impedance spectroscopy (EIS), DC polarization, and linear sweep voltammetry (LSV) measurement were carried out using a potentiostat (Gamry Reference [600] +). The transference numbers of the electrolytes were obtained through potentiostatic polarization method with Li j j Li symmetric cells.…”