Non-flammable Liquid Electrolyte Research Articles

A self-adaptive inorganic in-situ separator by particle crosslinking for nonflammable lithium-ion batteries

All-safe liquid-state lithium-ion batteries (ASLS-LIBs) is of great interest as they can potentially combine the safety of all-solid-state batteries with the high performance and low manufacturing cost of traditional liquid-state LIBs. However, the practical success of ASLS-LIBs is bottlenecked by the lack of advanced separator technology that can simultaneously realize high performances in puncturing-tolerability, fire-resistance, and importantly, wetting-capability with non-flammable liquid-electrolytes. Here, we propose a concept of inorganic in-situ separator (IISS) by hybrid-sol physical crosslinking directly onto the electrode surface to address the above challenges. Particularly, the hybrid-sol is designed with silica nanoparticles as the building block and poly(vinylidene difluoride) nanoparticles as the crosslinking agent. The critical factors for controlling the IISS microstructures and properties have been systematically investigated. The advantages of the IISS have been confirmed by its fast wetting with various fire-resistant liquid-electrolytes, customizable thickness and porous structures, robust interface with planar or three-dimensional (3D)-structured electrodes, and importantly, unexpected self-adaptability against puncturing. Enabled by the above merits, a fire-resistant ASLS-LIB is successfully assembled and demonstrated with stable electrochemical performance. This sol-crosslinked IISS may open an avenue for the studies on the next-generation separator technology, cell assembling, solid electrolyte processing as well as non-flammable secondary batteries.

Enhanced Safety, High-Rate and High-Voltage Performance of a Lithium-Ion Battery Using Nonflammable Liquid Electrolyte

These days lithium-ion battery (LIB) market is rapidly expanding by electric mobilities and stationary energy storage system industries. One of the biggest challenges in the research and development of advanced LIB is to achieve simultaneously outstanding energy density, cycle life, charge rate, and safety. For fast charging, battery chemistry and reaction kinetics are being evolved from the current hours scale toward minutes scale charging. In the LIB electrolyte perspective, the conventional carbonate-based liquid electrolyte has several limitations in safety and high-rate and high-voltage performance, due to low thermal and anodic stabilities under extreme operation conditions like high temperature, high-current, and high-voltage. To mitigate those issues, we have been developing new and safe electrolyte without any trade-off with cycling performance and energy density of Li-ion batteries. Herein, we present high-rate and high-voltage cycling performance and high safety of nickel-rich cathode-based lithium-ion full-cell fabricated with nonflammable liquid electrolyte. The correlation between the stability of nonflammable liquid electrolyte and its derived solid electrolyte interphase (SEI) and performance will be discussed in this meeting. Acknowledgements This research was supported by the National Research Foundation grant funded by the Ministry of Science and ICT (No. 2019R1A2C1084024).

Thermally Stable and Nonflammable Electrolytes for Lithium Metal Batteries: Progress and Perspectives

Thermally Stable and Nonflammable Electrolytes for Lithium Metal Batteries High safety is the precondition towards the practical application of lithium metal batteries. In article number 2100058, Jia-Qi Huang and co-workers prospectively analyze the thermal runaway mechanism of lithium metal batteries and summarize the measurement methods and research progress of thermally stable and nonflammable liquid electrolytes. The research of thermally stable and nonflammable electrolytes for lithium metal batteries is prospected.

Nonflammable, Low-Cost, and Fluorine-Free Solvent for Liquid Electrolyte of Rechargeable Lithium Metal Batteries.

Rechargeable metallic lithium batteries are considered as promising candidates for next-generation energy storage due to their high energy densities. However, safety concerns associated with electrolyte flammability and dendrite growth hinder their practical applications. Nonflammable liquid electrolytes have attracted significant attention recently, but they are mainly based on expensive ionic liquids, fluorinated solvents, or with highly concentrated salt. Here we design a novel trisalt electrolyte composed of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)-lithium bis(oxalato)borate (LiBOB)-LiPF6 in EC/PC solvent, which is not flammable even in contact with fire. Moreover, it creates unique protection of solid electrolyte interphase (SEI) film on lithium metal anode that allows 400 cycles of Li/Li(NiMnCo)1/3O2 cells with a capacity retention of 97.0% at 0.83 mA cm-2. This work illustrates that low-cost fluorine-free carbonate solvents can also realize nonflammable electrolyte with high performance, which opens new opportunities to promote safety and energy density of rechargeable lithium batteries simultaneously.