原著論文ピックアップ

Quantitative Characterization of Modified Lignin Using Solid-State 13C NMR Spectroscopy

Analytical Chemistry (accepted 15 Apr. 2025)
Haruka Sotome-Yukisada et al.

Solid-state 13 C nuclear magnetic resonance (NMR) spectroscopy with magic angle spinning (MAS) and direct polarization (DP) techniques is a valuable tool for quantitative and reliable characterization of lignin derivatives, specifically for determining these chemical structures and the degree of substitution upon chemical modification. In this study, the DPMAS 13 C NMR spectroscopy was used in a quantitative study of the esterifying reaction in lignin derivatives, which allowed the whole lignin structure to be determined. This quantitative evaluation system using DPMAS 13 C NMR spectroscopy can be widely utilized for lignin characterization without a specific chemical treatment or decomposition of lignin.

Rheology of Poly(ethylene oxide)-Based Slurries of Graphite Electrodes for All-Solid-State Polymer Batteries

ACS Applied Polymer Materials (accepted 28 Mar. 2025)
Kento Kimura, Mana Suzuki, Masayoshi Takano, Ryuta X. Suzuki, Yuichiro Nagatsu, Nana Takei, Yuka Oizumi, Yoichi Tominaga

This study examines in detail the rheological properties of aqueous graphite electrode slurries containing poly(ethylene oxide) (PEO)-based SPEs, which are critical for practical deployment but have not received much attention. The results demonstrate that the development of electrodes containing SPEs necessitates careful evaluation and optimization of the rheological properties of the slurries. The present study sheds significant light on the importance of specialized knowledge and techniques to obtain accurate and useful information on the non-Newtonian fluidity and viscoelasticity of battery electrode slurries containing SPE materials.

A highly salt concentrated ethylene carbonate-based self-standing copolymer electrolyte for solid-state lithium metal batteries

Journal of Materials Chemistry A (accepted 24 Jun. 2024) Open Access
Nantapat Soontornnon, Kento Kimura, Yoichi Tominaga

In this work, we achieved long cycling of SSLMBs utilizing an electrolyte based on CO2 -derived crosslinked random poly(ethylene carbonate- co -ethylene oxide- co -allyl glycidyl ether) (CP). The CP with as high as 29% crosslinking unit ratio (CP29 ) dissolving a high concentration of LiFSI can be obtained as a mechanically stable self-standing membrane and functions as an efficient electrolyte with a reasonable ionic conductivity. Remarkably, a Li//LiFePO4 SSLMB with the electrolyte as the self-standing separator enabled rechargeable operation for 400 cycles at 40 °C, with a coulombic efficiency of more than 99.5%.