Li-Rich Li-Si Alloy As A Lithium-Containing Negative Electrode Material Towards High Energy Lithium-Ion Batteries

Abstract

Lithium-ion batteries (LIBs) are generally constructed by lithium-including positive electrode materials, such as LiCoO2, and lithium-free negative electrode materials, such as graphite. Recently, lithium-free positive electrode materials, such as sulfur, are gathering great attention from their very high capacities, thereby significantly increasing the energy density of LIBs. Though the lithium-free materials need to be combined with lithium-containing negative electrode materials, the latter has not been well developed yet. In this work, the feasibility of Li-rich Li-Si alloy is examined as a lithium-containing negative electrode material. Li-rich Li-Si alloy is prepared by the melt-solidification of Li and Si metals with the composition of Li21Si5. By repeating delithiation/lithiation cycles, Li-Si particles turn into porous structure, whereas the original particle size remains unchanged. Since Li-Si is free from severe constriction/expansion upon delithiation/lithiation, it shows much better cyclability than Si. The feasibility of the Li-Si alloy is further examined by constructing a full-cell together with a lithium-free positive electrode. Though Li-Si alloy is too active to be mixed with binder polymers, the coating with carbon-black powder by physical mixing is found to prevent the undesirable reactions of Li-Si alloy with binder polymers, and thus enables the construction of a more practical electrochemical cell.

Silicon based lithium-ion battery anodes: A chronicle perspective review

“…The lithium-free cathodes need to be used in combination with the lithium-rich anodes as a full cell. Nishihara developed a Li-rich Li-Si alloy anode which showed a high initial lithium-extraction capacity of 1000 mAh g -1 [137]. Upon delithiation, the Li-Si particles turned into porous structure,…”

Systematic Investigation of Prelithiated SiO2 Particles for High-Performance Anodes in Lithium-Ion Battery

“…This process consumes an excess amount of cathode materials [6][7][8]13,18,19], which significantly reduces the total energy density of full-cells, thereby preventing their practical applications. In order to tackle this issue, researchers have proposed prelithiation of the electrode material, which directly compensates for the irreversible loss of lithium during the first cycle [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]. For example, Tarascon's…”

Pulsed Current Electrodeposition of Silicon Thin Films Anodes for Lithium Ion Battery Applications

“…Hence, the electrodeposited films show better performance and stable cycling as compared to sputtered silicon films which fail due to delamination of the films at the substrate-silicon interface [7,55]. A summary of XPS composition analysis of the Si thin films deposited at different frequencies along with depth profiling (increase in etching time) of the thin film and the calculated FIR loss as A summary of XPS composition analysis of the Si thin films deposited at different frequencies along with depth profiling (increase in etching time) of the thin film and the calculated FIR loss as per the reversible reaction of Si to form metastable Li 3.75 Si [56,57] and the irreversible reaction of Li with oxygen to form Li 2 O as shown in Figure 5 is given below.…”