Shen Yafei
Jiangsu Engineering and Technology Research Center of Environmental Cleaning Materials (ECM), Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (AEET), School of Environmental Science and Engineering, Nanjing University of Information Science & Technology , Nanjing 210044, China.
Department of Environmental Science and Technology, Tokyo Institute of Technology , Yokohama 226-8502, Japan.
J Agric Food Chem. 2017 Feb 8;65(5):995-1004. doi: 10.1021/acs.jafc.6b04777. Epub 2017 Jan 26.
Silica-rich rice husk (RH) is an abundant and sustainable agricultural waste. The recovery of value-added products from RH or its ash to explore an economic way for the valorization of agricultural wastes has attracted wide attention. For instance, RH can be converted to biofuels and biochars simultaneously via thermochemical processes. In general, the applications of RH biochars include soil remediation, pollutant removal, silicon battery materials, and so forth. This review concludes recent progress in the synthesis of RH-derived silicon materials for lithium-ion battery (LIB) applications. Silica nanomaterials produced from RH are initially discussed. RH amorphous silica can also be fabricated to crystal silicon used for battery materials via widely used magnesiothermic reduction. However, the RH-derived Si nanoparticles suffer from a low Coulombic efficiency in the initial charge/discharge and limited cycle life as anode materials due to high surface reactions and low thermodynamic stability. The synthesis of Si materials with nano/microhierarchical structure would be an ideal way to improve their electrochemical performances. Embedding nano-Si into 3D conductive matrix is an effective way to improve the structural stability. Among the Si/carbon composite materials, carbon nanotubdes (CNTs) are a promising matrix due to the wired morphology, high electronic conductivity, and robust structure. Additionally, CNTs can easily form 3D cross-linked conducting networks, ensuring effective electron transportation among active particles. Si nanomaterials with microhierarchical structures in which CNTs are tightly intertwined between the RH-derived Si nanoparticles have been proven to be ideal LIB anode materials.
富含二氧化硅的稻壳（RH）是一种丰富且可持续的农业废弃物。从RH或其灰分中回收增值产品，以探索农业废弃物增值的经济途径，已引起广泛关注。例如，RH可通过热化学过程同时转化为生物燃料和生物炭。一般来说，RH生物炭的应用包括土壤修复、污染物去除、硅电池材料等。本综述总结了用于锂离子电池（LIB）应用的RH衍生硅材料合成的最新进展。首先讨论了由RH制备的二氧化硅纳米材料。RH无定形二氧化硅也可通过广泛使用的镁热还原法制备成用于电池材料的晶体硅。然而，由于高表面反应和低热力学稳定性，RH衍生的硅纳米颗粒作为阳极材料在初次充放电时库仑效率较低，循环寿命有限。合成具有纳米/微层次结构的硅材料将是提高其电化学性能的理想方法。将纳米硅嵌入三维导电基体是提高结构稳定性的有效方法。在硅/碳复合材料中，碳纳米管（CNTs）由于其线状形态、高电子导电性和坚固的结构而成为一种很有前途的基体。此外，碳纳米管可以很容易地形成三维交联导电网络，确保活性颗粒之间的有效电子传输。已证明，具有微层次结构的硅纳米材料，其中碳纳米管紧密缠绕在RH衍生的硅纳米颗粒之间，是理想的LIB阳极材料。
