Performance Demonstration of MCMB-LiNiCoO₂ Cells Containing Electrolytes Designed for Wide Operating Temperature Range

Abstract

With the intent of improving the performance of Li-ion cells over a wide operating temperature range, we have investigated the use of co-solvents to improve the properties of electrolyte formulations. In the current study, we have focused upon evaluating promising electrolytes which have been incorporated into large capacity (7 Ah) prototype Li-ion cells, fabricated by Yardney Technical Products, Inc.The electrolytes selected for performance evaluation include the use of a number of esters as co-solvents, including methyl propionate (MP), ethyl propionate (EP), ethyl butyrate (EB), propyl butyrate (PB), and 2,2,2-trifluoroethyl butyrate (TFEB). The performance of the prototype cells containing the ester-based electrolytes was compared with an extensive data base generated on cells containing previously developed all carbonate-based electrolytes. A number of performance tests were performed, including determining (i) the discharge rate capacity over a wide range of temperatures, (ii) the charge characteristics, (iii) the cycle life characteristics under various conditions, and (iv) the impedance characteristics.

Exploring Classes of Co-Solvents for Fast-Charging Lithium-Ion Cells

“…[18][19][20][21][22][23] Ester-containing ternary or quaternary solvent blends have also been explored for low temperature applications, where conductivity and transport properties are especially limited. [24][25][26][27][28][29] The simple addition of a new co-solvent is a practical route to improving the performance of cells because it requires little change to existing supply chain and manufacturing infrastructure. This approach is therefore very appealing to industrial lithium-ion cell producers and forms the focus of the present work.…”

Electrolytes Design for Extending the Temperature Adaptability of Lithium‐Ion Batteries: from Fundamentals to Strategies

“…Some solvents such as EA, methyl propionate, DCM, and liquefied gas have been employed to enhance the LT performance of LIBs. [19,[208][209][210] Some heat-resistant solvents such as esters, nitriles, sulfones, etc. are used to widen the HT performance.…”

“…The Li/LiFePO 4 battery with the solid electrolyte demonstrated desirable cycle performance range from −20 °C to 100 °C, delivering a capacity of 143.3 mAh g −1 after 300 cycles at 100 °C. Recently, an in situ quasi-solid-state polyether electrolyte (SPEE) [244] was designed as [20,200,205,207,208,210,212,218,225,239,[241][242][243]245] an interface encapsulation on the cathode surface to suppress the side reactions. As shown in Figure 15e,f, the SSE was designed by a liquid ether-based precursor and tiny inorganic Lewis acids, which was favored in facilitating the ion conductivity and enabling the cell to show stable cycle performance at WT.…”

“…Figure 16. Typical electrolytes for LIBs at extremely WT ranging from −120 °C to 120 °C [20,200,205,207,208,210,212,218,225,239,[241][242][243]245]. …”