Towards a High-Power Si@graphite Anode for Lithium Ion Batteries through a Wet Ball Milling Process

Abstract

Silicon-based anodes are extensively studied as an alternative to graphite for lithium ion batteries. However, silicon particles suffer larges changes in their volume (about 280%) during cycling, which lead to particles cracking and breakage of the solid electrolyte interphase. This process induces continuous irreversible electrolyte decomposition that strongly reduces the battery life. In this research work, different silicon@graphite anodes have been prepared through a facile and scalable ball milling synthesis and have been tested in lithium batteries. The morphology and structure of the different samples have been studied using X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, and scanning and transmission electron microscopy. We show how the incorporation of an organic solvent in the synthesis procedure prevents particles agglomeration and leads to a suitable distribution of particles and intimate contact between them. Moreover, the importance of the microstructure of the obtained silicon@graphite electrodes is pointed out. The silicon@graphite anode resulted from the wet ball milling route, which presents capacity values of 850 mA h/g and excellent capacity retention at high current density (≈800 mA h/g at 5 A/g).

Stress-Relief Network in Silicon Microparticles and Composite Anodes for Durable High-Energy-Density Batteries

“…Deploying the Si/graphite or carbon composite anode has been attempted to relieve the volume-change-driven instability of Si anodes and has recently been suggested for rapid high-energy-density realization in the present application. − The graphite blending system can achieve both high energy density and stable cyclability, unlike independent graphite or Si anodes. Therefore, we prepared a composite anode composed of Si (or Si@pGN) and an AG mixture with a 2:8 weight ratio of Si (or Si@pGN) to AG (denoted as Si/AG28 and Si@pGN/AG28).…”

A Study to Explore the Suitability of LiNi0.8Co0.15Al0.05O2/Silicon@Graphite Cells for High-Power Lithium-Ion Batteries

“…The lower cut-off voltage was fixed at 0.05 V to limit the volume expansion experienced by silicon during prolonged cycling at low potentials that leads to poor stability [ 15 ]. During lithiation, below 0.2 V, the intercalation of lithium into graphite [ 29 , 30 ] and Si alloy formation take place. It was reported that, firstly, Li ~2 Si is formed at ca.…”

Nano-structured silicon and silicon based composites as anode materials for lithium ion batteries: recent progress and perspectives

“…Direct milling, chemical vapor deposition (CVD) and liquid-phase assembly are among the reported methods to prepare Si/graphite composites. 78 For example, Cabello et al 81 used a wet ball milling process to prepare a high-power Si@graphite composite. Here, an efficient dispersion and distribution of the particles is achieved with the addition of isopropyl alcohol during the synthesis procedure, and the use of few layer graphene as a conductive agent results in an electrode with an optimal microstructure that is able to mitigate Si volume changes during cycling.…”