cm9b05235_si_001.pdf (1.88 MB)
Structural Analysis of Sucrose-Derived Hard Carbon and Correlation with the Electrochemical Properties for Lithium, Sodium, and Potassium Insertion
journal contribution
posted on 2020-03-23, 21:29 authored by Kei Kubota, Saori Shimadzu, Naoaki Yabuuchi, Satoshi Tominaka, Soshi Shiraishi, Maria Abreu-Sepulveda, Ayyakkannu Manivannan, Kazuma Gotoh, Mika Fukunishi, Mouad Dahbi, Shinichi KomabaHard carbon possesses
the ability to store Li, Na, and K ions between
stacked sp2 carbon layers and voids (micropores). We have
explored hard carbon as a candidate for negative electrode materials
for Li-ion, Na-ion, and K-ion batteries. Hard carbon samples have
been prepared by carbonizing sucrose at different heat treatment temperatures
(HTTs) in the range of 700–2000 °C to make them structurally
suitable for reversible Li, Na, and K insertion. Structures and particle
morphology of the hard carbon samples synthesized at different HTTs
were systematically characterized using X-ray diffraction, small-angle
X-ray scattering, pair distribution function analysis, electron microscopy,
Raman spectroscopy, and electron spin resonance spectroscopy. All
these characterizations of hard carbon samples have revealed advanced
ordering of carbons and reduction of carbon defects with increasing
HTT. Thus, the average stacked carbon interlayer distance decreases,
the number of the stacking layers increases, the layered domains grow
in the in-plane direction, and interstitial voids enlarge. Electrochemical
properties of the hard carbons were examined in nonaqueous Li, Na,
and K cells. Potential profiles and reversible capacities upon galvanostatic
charge/discharge processes in nonaqueous cells are significantly different
depending on HTTs and different alkali metal ions. On the basis of
these findings, strategies to design high-capacity hard carbon negative
electrodes for high-energy-density Li-ion, Na-ion, and K-ion batteries
are discussed.