MCMB-LiNiCoAlO₂-Based Li-Ion Cells with Methyl Propionate-Based Electrolytes for Very Low Temperature Applications

Abstract

For a number of potential future missions, NASA is interested in obtaining Li-ion rechargeable cells that can operate over a wide temperature range. NASA is considering a surface mission to Europa, a moon of Jupiter, which is believed to have a liquid ocean beneath an icy surface layer. In support of such a potential mission, we are actively pursuing rechargeable Li-ion cells that are capable of operation over the temperature range of +40 o C to -60 o C (delivering up to 100 Wh/kg at -40 o C and 75 Wh/kg at -60 o C). For another application involving small notional explorer robots that would investigate the surface of Mars, low temperature cell capability (down to -70 o C) and survivability to ultra-low temperatures (-130 o C) would be mission enabling, due to the difficulty of implementing complex thermal management schemes for the batteries. Through the modification of electrolyte formulations, we have demonstrated that Li-ion cells are capable of operating down to very low temperatures (i.e., to -50 o C) while still providing reasonable performance at the warmer temperatures (up to +60 o C). In collaboration with Enersys/Quallion, LCC we have previously demonstrated improved low temperature performance of MCMB-LiNiCoAlO 2 -based prototype cells containing electrolytes with methyl propionate (MP) and ethyl butyrate (EB) 1 , and MP-based electrolytes with various additives. 2 Excellent performance has been demonstrated with these cells at discharge rates of 5C at -40 o C and 20C at -20 o C. More recently, we have studied the influence of electrolyte type upon the likelihood of lithium plating in these cells when charging at low temperatures. 3 To meet the requirements of potential upcoming missions, we have continued the investigation of methyl propionate (MP)-based electrolyte formulations, as well as more traditional all carbonate-based low temperature electrolytes, in MCMB-LiNiCoAlO 2 -based prototype cells manufactured by Enersys/Quallion. Electrolytes with high ester content were evaluated with the intent of being able to provide ultra-low temperature operation and survivability. The all carbonate-based electrolytes were evaluated with the expectation that they would perform well when cycled continuously at low rates at -40 o C. To characterize these cells, we have performed discharge rate characterization over a wide range of temperatures (down to -90 o C). We have also focused upon evaluating the cells during long term cycling continuously at -40 o C, while monitoring lithium plating, if any, during charging. These studies have been augmented by basic electrochemical studies in three-electrode cells to further understand the influence of electrolyte type upon the relative electrode kinetics at these low temperatures. ACKNOWLEDGEMENT The work described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration (NASA) and supported by the NASA Game Changing Development Program. REFERENCES 1. M. C. Smart, B. V. Ratnakumar, M. R. Tomcsi, M. Nagata, V. Visco, and H. Tsukamoto, 2010 Power Sources Conference, Las Vegas, NV, June 16, 2010, Pages 191-194. 2. M. C. Smart, M. R. Tomcsi, C. Hwang, L. D. Whitcanack, B. V. Ratnakumar, M. Nagata, V. Visco, and H. Tsukamoto, “Improved Wide Operating Temperature Range of LiNiCoAlO 2 -Based Li-ion Cells with Methyl Propionate-Based Electrolytes”, 221 st Meeting of the Electrochemical Society, Seattle, WA, May 6-10, 2012. 3. M. C. Smart, F. C. Krause, J. –P. Jones, C. Hwang, L. D. Whitcanack, B. V. Ratnakumar, M. R. Tomcsi, and V. Visco, “The Impact of Additives upon the Propensity of Lithium Plating at Low Temperature in MCMB-LiNiCoAlO 2 -Based Li-Ion Cells with Methyl Propionate-Based Electrolytes”, 227 th Meeting of the Electrochemical Society, Chicago, Illinois, May 25-29, 2015 (Abstract #47562).