Core-shell Si@TiO2 nanosphere anode by atomic layer deposition for Li-ion batteries

Abstract

Silicon (Si) has been regarded as next-generation anode for high-energy lithium-ion batteries (LIBs) due to its high Li storage capacity (4200 mA h g-1). However, the mechanical degradation and resultant capacity fade critically hinder its practical application. In this regard, we demonstrate that nanocoating of Si spheres with a 3 nm titanium dioxide (TiO 2) layer via atomic layer deposition (ALD) can utmostly balance the high conductivity and the good structural stability to improve the cycling stability of Si core material. The resultant sample, Si@TiO 2-3 nm core-shell nanospheres, exhibits the best electrochemical performance of all with a highest initial Coulombic efficiency and specific charge

A Bioinspired Nanofibrous Titania/Silicon Composite as an Anode Material for Lithium‐Ion Batteries

“…For instance, titania/silicon nanocomposites with silicon nanoparticles encapsulated in the mesoporous titania matrix were synthesized by a simple hydrolysis method combined with a magnesiothermic reduction process, by a sol–gel approach, or by a hydrothermal method . Additionally, titania‐coated silicon nanowires, silicon nanospheres, and silicon nanotube composites with core–shell structures prepared through an atomic layer deposition (ALD) process showed remarkably improved performances when used as anode materials for LIBs . Furthermore, porous titania/silicon nanofibers composed of titania and silicon nanoparticles were prepared by a sulfur‐templating approach combined with electrospinning, with the aim of enhancing the anodic performances of LIBs .…”

“…The pure silicon nanofiber (Figure S9a in the Supporting Information) becomes seriously pulverized and loose after repeated discharge/charge processes. In contrast, the fibrous structure of the titania‐54.3 %‐silicon composite (Figure S9 b in the Supporting Information) remains relatively integrated, and pulverization of the silicon nanoparticles is alleviated; this is ascribed to the titania coating layer on the surface of the silicon nanofiber, which serves not only as a lithium insertion/extraction host, but also buffers huge volume changes to silicon during repeated lithiation/delithiation processes . Therefore, better electrochemical performances were achieved by the titania‐54.3 %‐silicon composite.…”

Highly Porous Si Nanoframeworks Stabilized in TiO2 Shells and Enlaced by Graphene Nanoribbons for Superior Lithium‐Ion Storage

“…The core‐shell structure of Si@TiO 2 is well proved by the TEM image in Figure a, b, it is clearly that TiO 2 clamping layers are deposited on the surface of Si nanoparticles with a uniform thickness about 8 nm. It is noteworthy that the “inherent” silicon oxide (SiO x ) layer on the surface of Si cannot be observed under the present resolution, indicating that its thickness is extremely thin if exists . As for the HRTEM image in Figure c, it shows the interplanar distance of 0.314 nm (Si core) and 0.352 nm (TiO 2 shell), which are associated with the (111) planes of Si and (101) planes of anatase TiO 2 , respectively, in agreement with the XRD analysis.…”

Inverse‐direction Growth of TiO2 Microcones by Subsequent Anodization in HClO4 for Increased Performance of Lithium‐Ion Batteries

“…To improve its electrochemical performance, various types of nanostructured TiO 2 including nanospheres, nanosheets, nanotubes, and nanobelts have been fabricated to reduce the Li‐ion diffusion length in the solid phase. In addition, composite electrodes based on TiO 2 with high capacity or conductivity materials, including Si or graphene have been extensively investigated …”