In this work, we present the electrochemical behavior and microstructural analysis of silicon oxycarbide (SiOC) ceramics influenced by an addition of polystyrene (PS). Polymer-derived ceramics were obtained by pyrolysis (1000°C, Ar atmosphere) of different polysiloxanes prepared by sol–gel synthesis. This method is very effective to obtain desired composition of final ceramic. Two alkoxysilanes phenylthriethoxysilane and diphenyldimethoxysilane were used as precursors. Before pyrolysis polysiloxanes were mixed with PS using toluene as a solvent. Blending with PS affects the microstructure and free carbon content in the final ceramic material. Free carbon phase has been confirmed to be a major lithium storage host. Nevertheless, we demonstrate here that capacity does not increase linearly with increasing carbon content. We show that the amount of SiO₄ units in the SiOC microstructure increases the initial capacity but decreases the cycling stability and rate capability of the material. Furthermore, the microstructure of the free carbon influences the electrochemical performance of the ceramic: More ordered graphitic clusters favor better rate capability performance.

中文翻译：

---

与聚苯乙烯共混对SiOC陶瓷微观结构和电化学性能的影响

在这项工作中，我们介绍了受添加聚苯乙烯 (PS) 影响的碳氧化硅 (SiOC) 陶瓷的电化学行为和微观结构分析。通过溶胶-凝胶合成制备的不同聚硅氧烷的热解（1000°C，Ar 气氛）获得聚合物衍生陶瓷。该方法对于获得所需的最终陶瓷成分非常有效。两种烷氧基硅烷苯基三乙氧基硅烷和二苯基二甲氧基硅烷用作前体。在热解之前，使用甲苯作为溶剂将聚硅氧烷与 PS 混合。与 PS 混合会影响最终陶瓷材料中的微观结构和游离碳含量。已确认游离碳相是主要的储锂主体。尽管如此，我们在此证明容量不会随着碳含量的增加而线性增加。_{SiOC 微结构中的4 个}单元增加了初始容量，但降低了材料的循环稳定性和倍率性能。此外，游离碳的微观结构影响陶瓷的电化学性能：更有序的石墨簇有利于更好的倍率性能。