Pushing the thermal limits of Li-ion batteries. (October 2019)

• Record Type: Journal Article
• Authors: Kohlmeyer, Ryan R.; Horrocks, Gregory A.; Blake, Aaron J.; Yu, Zhenning; Maruyama, Benji; Huang, Hong; Durstock, Michael F.
• Is Part Of: Nano energy. Volume 64(2019)
• Publication Date: 2019-10
• Subjects: Energy storage -- High temperature batteries -- Li-ion batteries; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2019.103927
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Conventional Li-ion batteries are severely limited in high temperature applications mainly due to the poor thermal stability of the separator membrane (shrinkage/shutdown) and electrolyte decomposition in the full-cell. We have demonstrated a high temperature Li-ion system capable of good rate performance from 20 to 120 °C, well beyond the typical 60 °C limit of traditional Li-ion batteries. We have developed a printable and highly flexible Al2 O3 -poly(vinylidene fluoride) nanoporous separator membrane (Pyrolux™) infiltrated with a carefully designed high boiling point lithium bis(oxoalato)borate-based (LiBOB) liquid electrolyte. This unique electrolyte/membrane combination can offer a substantial safety advantage over conventional polyolefin separators embedded with liquid electrolyte, such as reduced flammability and enhanced dimensional stability at high temperature. Li//LiFePO4 and Li//graphite half-cells were tested at 120 °C and achieved reversible capacities of 155 and 340 mA h/g, respectively, with Coulombic efficiencies (CEs) > 99.4%. To date, reports on high temperature Li-ion full-cells have been limited mainly due to a combination of poor thermal stability of the separator membrane, accelerated side reactions, and solid-electrolyte interphase reformation. By utilizing our membrane and electrolyte, LiFePO4 //graphite full-cells were successfully demonstrated for the first time at 120 °C with excellent cyclability, representing a major step forward in the development of high temperature Li-ion batteries. Graphical abstract: Image 1 Highlights: A novel approach to Li-ion batteries enables high-temperature cyclability without compromising room-temperature performance. The combination of a highly thermally stable separator and electrolyte allow extended cycling at temperatures up to 120 °C. Separator and electrolyte combination is noncombustible under direct flame exposure indicating increased battery safety.