New insights on lithium storage in silicon oxycarbide/carbon composites: Impact of microstructure on electrochemical properties

被引：24

作者：

Knozowski, Dominik ^{[1
]}

Graczyk-Zajac, Magdalena ^{[2
,3
]}

Vrankovic, Dragoljub ^{[2
]}

Trykowski, Grzegorz ^{[4
]}

Sawczak, Miroslaw ^{[5
]}

De Carolis, Dario M. ^{[2
]}

Wilamowska-Zawlocka, Monika ^{[1
]}

机构：

[1] Gdansk Univ Technol, Fac Chem, Dept Energy Convers & Storage, Narutowicza 11-12, PL-80233 Gdansk, Poland

[2] Tech Univ Darmstadt, Fachbereich Mat & Geowissensch, Otto Berndt Str 3, D-64287 Darmstadt, Germany

[3] EnBW Energie Baden Wurttemberg AG, Durlacher Allee 93, D-76131 Karlsruhe, Germany

[4] Nicolaus Copernicus Univ Torun, Fac Chem, PL-87100 Torun, Poland

[5] Polish Acad Sci, Inst Fluid Flow Machinery, Fiszera 14, PL-80231 Gdansk, Poland

来源：

COMPOSITES PART B-ENGINEERING | 2021年 / 225卷

关键词：

Polymer derived ceramics; Composites; Graphite; Li-ion battery; Sol-gel synthesis; ANODE MATERIAL; HIGH-CAPACITY; ELECTRODE MATERIALS; NATURAL GRAPHITE; SIOC; CARBON; INTERCALATION; PERFORMANCE; BATTERIES; MECHANISM;

D O I：

10.1016/j.compositesb.2021.109302

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

In this work, we study the impact of the preceramic precursor vinyltriethoxysilane (VTES) on the electrochemical performance of silicon oxycarbide (SiOC) glass/graphite composites. We apply an innovative approach based on high-power ultrasounds in order to obtain highly homogenous composites with a uniform distribution of small graphitic flakes. This procedure enhances gelation and drying of VTES-based preceramic polymer/graphite blends. The SiOC/graphite composites reveal stable capacities (up to 520 mAh g-1 after 270 cycles), which are much higher than the sum derived from the ratio of the components. Additionally, the first cycle Coulombic efficiencies obtained for the composites are 15% higher than that of the pristine VTES-based SiOC ceramic. These properties are identified as the synergistic effect, originated from the addition of graphite to VTES-based SiOCs. Interestingly, such improvement in electrochemical performance is not noticed in the case of analogous SiOC/ graphite composites based on phenyltriethoxysilane (PhTES) precursor. The microstructural investigation of the composites based on two different preceramic precursors using solid-state 29Si NMR and Raman Spectroscopy unveils the reason for such discrepancy in their electrochemical behaviour.

引用

页数：11

共 66 条

[1] Synthesis and electrochemical performance of a polymer-derived silicon oxycarbide/boron nitride nanotube composite [J].