Barrio Rocío, González Nieves, Portugal Álvaro, Morant Carmen, Gandía José Javier
Centro de Investigaciones Energéticas, Mediambientales y Tecnológicas, Avenida Complutense 40, CP-28040 Madrid, Spain.
Department of Applied Physics, Instituto de Ciencias de Materiales Nicolás Cabrera, Autonomous University of Madrid, CP-28049 Madrid, Spain.
Nanomaterials (Basel). 2022 Dec 9;12(24):4400. doi: 10.3390/nano12244400.
Graphite is the material most used as an electrode in commercial lithium-ion batteries. On the other hand, it is a material with low energy capacity, and it is considered a raw critical material given its large volume of use. In the current energy context, we must promote the search for alternative materials based on elements that are abundant, sustainable and that have better performance for energy storage. We propose thin materials based on silicon, which has a storage capacity eleven times higher than graphite. Nevertheless, due to the high-volume expansion during lithiation, it tends to crack, limiting the life of the batteries. To solve this problem, hydrogenated amorphous silicon has been researched, in the form of thin film and nanostructures, since, due to its amorphous structure, porosity and high specific surface, it could better absorb changes in volume. These thin films were grown by plasma-enhanced chemical vapor deposition, and then the nanowires were obtained by chemical etching. The compositional variations of films deposited at different temperatures and the incorporation of dopants markedly influence the stability and longevity of batteries. With these optimized electrodes, we achieved batteries with an initial capacity of 3800 mAhg and 82% capacity retention after 50 cycles.
石墨是商业锂离子电池中最常用作电极的材料。另一方面，它是一种能量容量较低的材料，鉴于其大量的使用，它被视为一种关键原材料。在当前的能源背景下，我们必须推动基于丰富、可持续且具有更好储能性能的元素来寻找替代材料。我们提出基于硅的薄膜材料，其存储容量比石墨高11倍。然而，由于锂化过程中的高体积膨胀，它容易开裂，限制了电池的寿命。为了解决这个问题，已经对氢化非晶硅进行了研究，其形式为薄膜和纳米结构，因为由于其非晶结构、孔隙率和高比表面积，它可以更好地吸收体积变化。这些薄膜通过等离子体增强化学气相沉积生长，然后通过化学蚀刻获得纳米线。在不同温度下沉积的薄膜的成分变化以及掺杂剂的掺入显著影响电池的稳定性和寿命。使用这些优化的电极，我们实现了初始容量为3800 mAhg且在50次循环后容量保持率为82%的电池。
