A Green and Facile Way to Prepare Granadilla-Like Silicon-Based Anode Materials for Li-Ion Batteries
A Green and Facile Way to Prepare Granadilla-Like Silicon-Based Anode Materials for Li-Ion Batteries
复制标题
DOI：
10.1002/adfm.201503777
复制
发表时间：
2016-01-20
影响因子：
19
通讯作者：
Liu, Huakun
中科院分区：
文献类型：
--
作者：
Zhang, Lei;Rajagopalan, Ranjusha;Liu, Huakun
蛋黄壳结构的碳@空隙@硅（CVS）阳极材料，其中内部硅纳米粒子和外部碳壳之间产生空隙空间，被认为是锂离子电池的有希望的候选材料。到目前为止，所有以前的蛋黄壳复合材料都是通过模板法制造的，其中SiO2层充当牺牲层，并通过使用有毒氢氟酸的选择性蚀刻方法产生空隙。然而，这种方法复杂且有毒。在此，报道了一种绿色且简便的合成西番莲状外部碳涂层封装的硅/碳微球，该微球由互连的碳框架支撑的CVS纳米珠组成。硅西番莲是通过改进的模板法制备的，其中选择碳酸钙作为牺牲层，乙炔作为碳前驱体。因此，可以通过用稀盐酸去除CaCO3来形成这些CVS纳米珠内部和之间的空隙空间。所制备的硅含量为30%的硅西番莲在250 mA g(-1)电流密度下循环200次后可逆容量约为1100 mAh g(-1)。此外，该复合材料在1000和2000 mA g(-1)的电流密度下分别表现出约830和700 mAh g(-1)的优异倍率性能。
A yolk-shell-structured carbon@void@silicon (CVS) anode material in which a void space is created between the inside silicon nanoparticle and the outer carbon shell is considered as a promising candidate for Li-ion cells. Untill now, all the previous yolk-shell composites were fabricated through a templating method, wherein the SiO2 layer acts as a sacrificial layer and creates a void by a selective etching method using toxic hydrofluoric acid. However, this method is complex and toxic. Here, a green and facile synthesis of granadilla-like outer carbon coating encapsulated silicon/carbon microspheres which are composed of interconnected carbon framework supported CVS nanobeads is reported. The silicon granadillas are prepared via a modified templating method in which calcium carbonate was selected as a sacrificial layer and acetylene as a carbon precursor. Therefore, the void space inside and among these CVS nanobeads can be formed by removing CaCO3 with diluted hydrochloric acid. As prepared, silicon granadillas having 30% silicon content deliver a reversible capacity of around 1100 mAh g(-1) at a current density of 250 mA g(-1) after 200 cycles. Besides, this composite exhibits an excellent rate performance of about 830 and 700 mAh g(-1) at the current densities of 1000 and 2000 mA g(-1), respectively.