Xiaosi Zhou

Binding SnO2 Nanocrystals in Nitrogen‐Doped Graphene Sheets as Anode Materials for Lithium‐Ion Batteries

Hybrid anode materials for Li-ion batteries are fabricated by binding SnO2 nanocrystals (NCs) in nitrogen-doped reduced graphene oxide (N-RGO) sheets by means of an in situ hydrazine monohydrate vapor reduction method. The SnO2NCs in the obtained SnO2NC@N-RGO hybrid material exhibit exceptionally high specific capacity and high rate capability. Bonds formed between graphene and SnO2 nanocrystals limit the aggregation of in situ formed Sn nanoparticles, leading to a stable hybrid anode material with long cycle life.

Ultra‐Uniform SnOx/Carbon Nanohybrids toward Advanced Lithium‐Ion Battery Anodes

Ultra-uniform SnOx/carbon nanohybrids for lithium-ion batteries are successfully prepared by solvent replacement and subsequent electrospinning. The resulting 1D nanostructure with Sn-N bonding between the SnOx and N-containing carbon nanofiber matrix can not only tolerate the substantial volume change and suppress the aggregation of SnOx, but also enhances the transport of both electrons and ions for the embedded SnOx, thus leading to high cycling performance and rate capability.

Co3S4 porous nanosheets embedded in graphene sheets as high-performance anode materials for lithium and sodium storage

Co3S4 porous nanosheets embedded in flexible graphene sheets have been synthesized through a simple freeze-drying and subsequent hydrazine treatment process. The robust structural stability of the as-prepared three-dimensional sandwich-like Co3S4–PNS/GS composite affords improved rate performance and cycling stability for both lithium and sodium storage.

Electrospun silicon nanoparticle/porous carbon hybrid nanofibers for lithium-ion batteries.

Lithium-ion batteries (LIBs) are attracting increasing research attention as energy storage devices due to their high energy density and long cycle life. [ 1–15 ] For anode materials, silicon has been proposed to be one of the most promising candidates because of its highest theoretical capacity of ∼ 4200 mA h g − 1 for Li 4.4 Si, low electrochemical potential ( < 0.5 V vs Li + /Li), low cost, and abundant in nature as well as mature mass production. [ 16–20 ] However, the practical application of silicon as anode materials for LIBs is still quite challenging by the poor cyclability resulting from both pulverization of particles and electrical disconnection from the current collector caused by the large volume change ( > 300%) during the lithium insertion and extraction processes. [ 21–28 ]

A robust composite of SnO2 hollow nanospheres enwrapped by graphene as a high-capacity anode material for lithium-ion batteries

Graphene enwrapped SnO2 hollow nanospheres have been developed with combination of two desirable components: hollow nanostructures and graphene coating. The as-obtained SnO2-HNS/G becomes robust and exhibits stable cyclability and superior high-rate capability.

Efficient 3D Conducting Networks Built by Graphene Sheets and Carbon Nanoparticles for High-Performance Silicon Anode

The utilization of silicon particles as anode materials for lithium-ion batteries is hindered by their low intrinsic electric conductivity and large volume changes during cycling. Here we report a novel Si nanoparticle-carbon nanoparticle/graphene composite, in which the addition of carbon nanoparticles can effectively alleviate the aggregation of Si nanoparticles by separating them from each other, and help graphene sheets build efficient 3D conducting networks for Si nanoparticles. Such Si-C/G composite shows much improved electrochemical properties in terms of specific capacity and cycling performance (ca. 1521 mA h g(-1) at 0.2 C after 200 cycles), as well as a favorable high-rate capability.

Wet milled synthesis of an Sb/MWCNT nanocomposite for improved sodium storage

A uniform mixture of nano-sized Sb particles and MWCNTs is achieved by using wet milling to provide fast ionic diffusion and electronic transportation, and the cycling performance and rate capability of the as-obtained nanocomposite are significantly improved when tested as an anode material for sodium-ion batteries.

Spin-coated silicon nanoparticle/graphene electrode as a binder-free anode for high-performance lithium-ion batteries

Si has been considered as a promising anode material but its practical application has been severely hindered due to poor cyclability caused by the large volume change during charge/discharge. A new and effective protocol has been developed to construct Si nanoparticle/graphene electrodes with a favorable structure to alleviate this problem. Starting from a stable suspension of Si nanoparticles and graphene oxide in ethanol, spin-coating can be used as a facile method to cast a spin-coated Si nanoparticle/graphene (SC-Si/G) film, in which graphene can act as both an efficient electronic conductor and effective binder with no need for other binders such as polyvinylidenefluoride (PVDF) or polytetrafluoroethylene (PTFE). The prepared SC-Si/G electrode can achieve a high-performance as an anode for lithium-ion batteries benefiting from the following advantages: i) the graphene enhances the electronic conductivity of Si nanoparticles and the void spaces between Si nanoparticles facilitate the lithium ion diffusion, ii) the flexible graphene and the void spaces can effectively cushion the volume expansion of Si nanoparticles. As a result, the binder-free electrode shows a high capacity of 1611 mA·h·g−1 at 1 A·g−1 after 200 cycles, a superior rate capability of 648 mA·h·g−1 at 10 A·g−1, and an excellent cycle life of 200 cycles with 74% capacity retention.

A selenium-confined microporous carbon cathode for ultrastable lithium–selenium batteries

A novel selenium–carbon composite has been fabricated by embedding selenium in metal–organic framework-derived microporous carbon polyhedra. Such interconnected microporous carbon polyhedra possess a large surface area and pore volume to effectively confine Se, and suppress the dissolution of polyselenides in the electrolyte. This selenium–carbon composite shows ultrastable cycling performance when used as a cathode material for lithium–selenium batteries.

Shape controlled synthesis of palladium nanocrystals by combination of oleylamine and alkylammonium alkylcarbamate and their catalytic activity

The shape of Pd nanocrystals (NCs) can be controlled by combination of oleylamine (OAm) and alkylammonium alkylcarbamate (AAAC), and Pd spheres, tetrahedra and multipods have been synthesized. The multipods and tetrahedra are much more active than the spheres for hydrogenation reactions.