期刊
JOURNAL OF POWER SOURCES
卷 249, 期 -, 页码 219-230出版社
ELSEVIER
DOI: 10.1016/j.jpowsour.2013.09.087
关键词
Lithium ion; Batteries; Chemical diffusion; GITT; Silicon-oxycarbide
资金
- Ceramics Program of the Division of Materials Research at the National Science Foundation [DMR-0907108]
- Direct For Mathematical & Physical Scien
- Division Of Materials Research [0907108] Funding Source: National Science Foundation
Experiments with silicon-oxycarbide, an anode material for Li-ion batteries, are compared with a rigorous solution for time-dependent diffusion profiles in spherical particles, which is supplemented by finite element analyses of cuboid shaped particles. In this way a value for the chemical diffusivity D = 1.8 x 10(-18) -4.2 x 10(-18) m(2) s(-1) across the entire range of the state-of-charge is obtained. The method consists of galvanostatic titrations, where a constant current injection is followed by the measurement of the galvanic potential in open circuit relaxation, at various values of the state-of-charge. Comparison with theory shows that the relaxation time varies with the state-of-charge because the particles have variable size: small particles have short relaxations and dominate the low values of the state-of-charge. The theoretical results have additional notable features. We show that the solution for the spherical particles can be represented to a very good approximation by a single time constant of exponential relaxation. Its value is significantly slower than the results for one-dimensional solutions. The relaxation time is independent of the injection current and the state-of-charge, imparting significant generality to the results. (C) 2013 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据