Dichlorosilane-derived nano-silicon inside hollow carbon spheres as a high-performance anode for Li-ion batteries

Abstract

A novel and cost-effective synthesis of silicon nanocrystallites (<10 nm) sealed in hollow carbon spheres (nc-Si@HCS) is developed as a promising anode material for high-performance Li-ion batteries (LIBs). The preparation method involves dichlorosilane (H2SiCl2) as widely available feedstock, to form a hydrogen-rich polysiloxane as a precursor for the production of large quantities of silicon nanoparticles. The final electrode material is composed of agglomerated 5 nm sized silicon nanoparticles encapsulated within hollow micro-sized carbon structures. A high specific capacity of 1570 mA h gelectrode−1 at 0.25 A g−1 with a capacity retention of 65% after 250 deep discharge cycles and a reversible high areal capacity of up to 4 mA h cm−2 at a total mass loading of 3.2 mg cm−2 impressively demonstrate the excellent features of this novel anode material. We performed a detailed structural as well as electrochemical characterization in different electrolytes. Post mortem investigations help to understand the degradation mechanism in our material. The study herein heralds a new approach to structurally design advanced negative electrode materials with the potential to increase the specific energy of LIBs and to boost future electro-mobility technology

Lithium-Ion Battery Anodes of Stacked Nanowire Laminate for Ultrahigh Areal Capacities

“…Figure presents the plots of the areal capacity against the active materials areal mass loading (the detailed data is shown in Table S2). These plots display the recent studies of alloy anode materials (data taken from refs , , , , , , , and − ), which achieve or overpass the areal mass loading level of commercial graphite, indicating that the stacked Ge/Cu nanowire laminate electrode reaches a new level of areal mass loading of 14.8 mg cm –2 , being 1.5 times higher than that of the second place. Moreover, stacked Ge/Cu nanowire laminate electrode with 14.8 mg cm –2 provided a reversible capacity of 16 mA h per unit area that utilized Ge of approximately 80%, ranking first place among all of the alloy anodes reported in the literature.…”

“…Comparison of stacked Ge/Cu nanowire laminate electrode and reported Ge, Si, Sn anodes at the rate of around 0.1 C. Data taken from refs , , , , , , , and − . The detailed data is shown in Table S1.…”

Green, Template-Less Synthesis of Honeycomb-like Porous Micron-Sized Red Phosphorus for High-Performance Lithium Storage

“…To evaluate the practical application capability of our designed anode material, − the electrochemical performance of the HPRP-36 electrode with active material loading of about 2.0 mg cm –2 at 0.05 A g –1 was also tested. It can deliver an areal capacity of 3.3 mA h cm –2 in the second cycle and remains at 2.0 mA h cm –2 after 50 cycles.…”

Boosting the cell performance of the SiOx@C anode material via rational design of a Si‐valence gradient

“…Zheng's group 15 reported optimal thickness (~5 nm) of the coating layer for Si particles with a particle size of ~30 nm in terms of Li‐ion kinetics and mechanical stability at the interface. Synergistic effects originating from different Si valances in SiO x are gradually becoming a vitally important strategy for high‐performance Si‐based materials, in which Si valance can be mediated via self‐oxidation, 15 dismutate reaction, 16,17 or silicon reagents 18 …”

“…18 In fact, a series of intermediate states of SiO x (0 < x < 2) inevitably form on the surface or inside the particle undergoing high-temperature calcination, and the oxygen vacancy content of SiO x has a profound effect on electrochemical performances. 8,19 The larger oxygen vacancy content in SiO x reflects the high valence state of the Si element. SiO x with different oxygen content demonstrates nonlinear phenomena in volume expansion, internal stress/strain, and SEI-film evolution upon performing a lithiated process.…”