Conductive Rigid Skeleton Supported Silicon as High-Performance Li-Ion Battery Anodes

Abstract

A cost-effective and scalable method is developed to prepare a core-shell structured Si/B(4)C composite with graphite coating with high efficiency, exceptional rate performance, and long-term stability. In this material, conductive B(4)C with a high Mohs hardness serves not only as micro/nano-millers in the ball-milling process to break down micron-sized Si but also as the conductive rigid skeleton to support the in situ formed sub-10 nm Si particles to alleviate the volume expansion during charge/discharge. The Si/B(4)C composite is coated with a few graphitic layers to further improve the conductivity and stability of the composite. The Si/B(4)C/graphite (SBG) composite anode shows excellent cyclability with a specific capacity of ∼822 mAh·g(-1) (based on the weight of the entire electrode, including binder and conductive carbon) and ∼94% capacity retention over 100 cycles at 0.3 C rate. This new structure has the potential to provide adequate storage capacity and stability for practical applications and a good opportunity for large-scale manufacturing using commercially available materials and technologies.

Mesoporous silicon sponge as an anti-pulverization structure for high-performance lithium-ion battery anodes

“…Figure 4a shows the cyclic voltammetry curve of an anode prepared from the MSS material. The curves appear very similar to those obtained from standard crystalline Si 3,16 , and they are consistent with the crystalline XRD pattern shown in Fig. 2d.…”

“…2d. The cathodic peak at B0.21 V and the anodic peaks at B0.32 and B0.49 V are characteristic of amorphous Si, and the cathodic peak at B0 V is characteristic of both crystalline and amorphous Si 16 . In the first cathodic scan, only crystalline Si exists, so only one peak at B0 V is observed.…”

Insights into the conversion behavior of SiO-C hybrid with pre-treated graphite as anodes for Li-ion batteries

“…In the first cathodic scan, an intense peak located at $0.75 V is observed, corresponding to the formation of the SEI [28]. The cathodic peaks at 0.10 V and the anodic peaks at 0.12 V are attributed to graphite in the composites [29]. The sharp cathodic peaks closing to 0 V are attributed to the phase transition of Li x Si to Li 15 Si 4 [30].…”

Deposition of silver nanoparticles into silicon/carbon composite as a high-performance anode material for Li-ion batteries

“…Although the novel nanostructure Si and Si/C composite anodes show better electrochemical performance than pure bulk Si anode, these anodes still have drawback of severe capacity fading at high current densities due to their relative poor electrical conductivity. Therefore, electrical conductive additives (e.g., Cu [15], Ni [16], and B 4 C [17]) are exploited to improve the rate performance of Si-based anodes.…”