Benchmarking the Safety Performance of Organic Electrolytes for Rechargeable Lithium Batteries: A Thermochemical Perspective

Abstract

Developing nonflammable organic electrolytes has been regarded as one of the most valuable strategies for tackling the safety issues of rechargeable lithium batteries. However, a quantitative and precise evaluation of electrolyte safety remains challenging mostly because of the inconsistent measurement conditions and the lack of a basic reference system. In this work, we performed a benchmark study on the safety of organic electrolytes by characterizing with cone calorimetry the thermochemistry of various types of single-solvent electrolytes. An intrinsically safe organic electrolyte should show simultaneous low total heat release, low maximum heat release rate, long time to ignition, and short self-extinguishing time. Experimentally, a “cocktail” therapy combining polyfluorinated solvents and high-boiling point solvents is found to be the optimal choice for composing nonflammable electrolytes. Our results help to identify promising electrolyte components and shed light on the reasonable design of high-safety organic electrolytes for advanced rechargeable batteries.

Recent progress in nonflammable electrolytes and cell design for safe Li-ion batteries

“…It collects thermophysical constants of materials including SET, total heat release (THR), maximum heat release rate (MHRR) and time to ignition (TTI) and is more accurate than manual SET testing. Yang et al 41 employed a cone calorimeter to compare the flammability of eight single solvent electrolytes and found that a combination of nonflammable polyfluorinated solvents and high boiling point solvents was the optimal choice for nonflammable electrolyte design with low THR, low MHRR, long TTI and short SET.…”

Highly loaded gold (Au) nanoseeds with uniform distribution on 3D carbon foam for long-cycle lithium-metal batteries

“…[1][2][3][4] As a result, various strategies have been successfully employed to suppress dendritic lithium growth in lithium-metal batteries (LMBs), [5][6][7][8] which is one of the critical causes that could occur safety issues. [9][10][11][12] In particular, carbon-based materials have shown great potential as lithium host materials. A diverse range of carbon materials such as graphene, carbon nanotubes (CNTs), carbon nanobers (CNFs), and carbon spheres have been used to effectively accommodate lithium due to their high conductivity, lithiophilicity, chemical/physical stability, and low gravimetric density.…”

Nitrogen Ion Implantation-Modified Cu Substrate for Stable Lithium Metal Anode

“…So, the stability of LMA plays a crucial role in the safety of lithium metal batteries (LMBs). 16,17 Various strategies have been made to modify the Cu substrate, such as high-temperature calcination, 18 spin coating, 19 chemical vapor deposition, 20 and electrospinning. However, most of these methods require complex design and material synthesis procedures, which will increase the complexity of the LMA fabrication process, while, in some cases, the large addition of inactive substances will reduce the energy density of the LMBs.…”

“…Severe dendrite growth and poor cycling stability will exist for Cu-hosted LMA, which will finally lead to battery short circuit, thermal runaway, , and even explosion or fire. So, the stability of LMA plays a crucial role in the safety of lithium metal batteries (LMBs). , …”