Keisuke Kanayama 교수

Carbonate esters such as dimethyl carbonate (DMC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) are widely used as electrolyte solvents in a lithium-ion battery (LIB) and are considered as one of potential fire causes. This study investigates a difference in gas-phase reactivities of DMC, EMC and DEC. Species measurements for oxidation (equivalence ratio of 1.0) and pyrolysis of DMC and DEC at maximum wall temperatures of Tw,max = 700–1300 K and atmospheric pressure were performed us

Ethylene carbonate (EC) and dimethyl carbonate (DMC) are important chemical substances of the lithium-ion battery (LIB) electrolytes. Although the carbonate esters are regarded as a cause of the LIB fires, there are few studies on the pyrolysis/combustion characteristics of EC. This study aims to investigate the pyrolysis characteristics of EC by performing theoretical calculations and species measurements, and to propose the first EC pyrolysis sub-mechanism. The theoretical calculations perform

Fire-risk assessment of lithium-ion batteries (LIBs) is an urgent task as the number and size of products using LIBs are both increasing. LIB electrolyte solvents consist of mixtures of flammable carbonate esters, such as ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC). This study aims to report the first EC combustion experiments (ignition delay time (IDT), CO laser absorption, and laminar flame speed measurements), and to provide a L

Trimethyl phosphate (TMP), an organophosphorus compound (OPC), is a promising fire-retardant candidate for lithium-ion battery (LIB) electrolytes to mitigate fire spread. This study aims to understand the mechanism of TMP unimolecular thermal decomposition to support the integration of a TMP chemical kinetic model into a LIB electrolyte surrogate model. Reactive intermediates and products of TMP thermal decomposition were experimentally detected using vacuum ultraviolet (VUV) synchrotron radiati

(2020). Study on Products from Fuel-rich Methane Combustion near Sooting Limit Temperature Region and Importance of Methyl Radicals for the Formation of First Aromatic Rings. Combustion Science and Technology. Ahead of Print.

Understanding how isomerism influences photoelectron spectra helps in the assignment and analysis of reactive mixtures, especially for heterocycles with numerous isomers. Threshold photoelectron spectra of lutidyl radical isomers, i. e., benzyl derivatives with a nitrogen heteroatom and a methyl substituent, are recorded using vacuum ultraviolet synchrotron radiation. The radicals are produced by flash pyrolysis from aminomethyl methylpyridine precursors. Experimental ionization energies are det

Carbonic acid (H₂CO₃) is a fundamental species in biological, ecological, and astronomical systems. However, its spectroscopic characterization is incomplete because of its reactive nature. The photoionization (PI) and the photoion mass-selected threshold photoelectron (ms-TPE) spectra of H₂CO₃ were obtained by utilizing vacuum ultraviolet (VUV) synchrotron radiation and double imaging photoelectron photoion coincidence spectroscopy. Two carbonic acid

The Cover Feature illustrates how the ionization energies of benzyl-type radicals are influenced by N- and CH3- substitution, a legacy inherited from their parent compounds. More information can be found in the Research Article by Patrick Hemberger and co-workers.

• Widely used LIB electrolyte solvents, EC/DMC, EC/EMC and EC/DEC, were investigated. • Carbonate esters remained dominant in pyrolysis gas at 600 K, even after 1000 s. • Laminar flame speeds were in the order of EC/DMC < EC/EMC ≈ EC/DEC. • Relative magnitude of laminar flame speed could be assessed by thermal diffusivity. • Liquid- and gas-based fire hazard of LIB electrolyte solvents were opposite. Fire safety has become a more serious concern for lithium-ion battery (LIB) applications with th