Metal Organic Frameworks and Porous Polymer Network-Based Matrices as Nonflammable Battery Electrolytes


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Due to their high energy densities, low self-discharge rates and low maintenance requirements, Lithium ion (Li-ion) batteries represent the preferred battery format, especially when compared to other rechargeable cells such as Ni-Cad and NiMH batteries. However, in order for Li-ion batteries to be effectively utilized for any application, their safety concerns need to be addressed. Li-ion battery safety issues typically relate to the thermal stability of the constituent materials. Li-ion batteries are thermodynamically unstable and the compatibility of the battery components is kinetically attained with the presence of the surface passivation films on the electrode surface. The decomposition of this solid electrolyte inter-phase (SEI) layer, resulting from the electrochemically reductive decomposition of the electrolyte on the graphite anode, can initialize exothermic reactions between the lithiated graphite anode and the electrolyte. When a cell is heated above a certain temperature, exothermic chemical reactions between the electrodes and the flammable electrolyte can occur and lead to an increase of the internal cell temperature. Therefore, Li-ion batteries are very sensitive to thermal and overcharge abuse and pose significant fire hazards. The overcharge of Li-ion batteries can lead to chemical and electrochemical reactions between battery components, gas release, and a rapid increase of the cell temperature. The overcharge can also trigger self-accelerating reactions in the batteries, which can lead to thermal runaway and possible explosion due to the use of flammable electrolytes. In short, rechargeable Lithium and Li-ion batteries can fail violently when subjected to an internal electrical short, are overheated, crushed, or when they are overcharged/overdischarged. Due to these failures, improvements in safety are urgently needed for Lithium and Li-ion batteries with the use of electrolytes based on nonflammable, room temperature ionic liquids. To address these safety concerns, nonflammable ionic liquids have gained interest recently. Although the results of studies on ionic liquids revealed that they could be used as promising electrolytes, further improvements are necessary. These improvements include increased conductivity and lower activation energy. If ionic liquids can be formed into an ordered structure and their ion conductive path can be regulated, the performance in batteries can be further improved while leveraging their safe, green and nonflammable attributes. framergy has recently started developing ionic liquid incorporated modified Metal-organic Frameworks (MOFs) and Porous Polymer Networks (PPNs) to serve as efficient electrolyte systems for Li-ion batteries. framergy’s novel class of MOFs and PPNs can provide ionic liquids with an ordered structure improving their ionic conductivity while lowering their activation energy. framergy is a startup nanomaterial company, which designs and manufactures MOFs and PPNs. Founded in 2011, framergy is the oldest coordination polymer company in the world. While there are many university MOF driven startups, framergy is the only Company in the material class with an investment from an industrial company commercializing MOFs at scale. Pilot scaling of its CONEKTIK MOFs is complete for Adsorbed Natural Gas (ANG) on vehicles, demonstrating the Company’s ability to translate fundamental government funded research into commercialization.

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Journal: TechConnect Briefs
Volume: 2, Materials for Energy, Efficiency and Sustainability: TechConnect Briefs 2018
Published: May 13, 2018
Pages: 63 - 66
Industry sector: Energy & Sustainability
Topic: Energy Storage
ISBN: 978-0-9975117-9-6