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Rao Juan

Bio: Rao Juan is an academic researcher from Hefei University of Technology. The author has contributed to research in topics: Anode & Battery (electricity). The author has an hindex of 4, co-authored 5 publications receiving 125 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the authors developed a simple approach to rationally design and controllably synthesize custard-apple-like Si@N, O-dual-doped carbon with hierarchical porosity.

118 citations

Journal ArticleDOI
TL;DR: In this article, a free-standing paper electrode was used as cathode material for Li-S batteries, which is a binder-free graphene-polypyrrole (PPy)/S-graphene (G-PPy/S-G) structural electrode was prepared by using the vacuum filtration method.

26 citations

Patent
22 Feb 2017
TL;DR: In this article, an anode material for Li-ion batteries and a preparation method thereof is described. But the preparation method is not described. And it is not shown how to obtain a large scale production can be achieved.
Abstract: The invention discloses an anode material for Li-ion batteries and a preparation method thereof. The anode material for Li-ion batteries is characterized in that silica nanoparticles are taken as raw materials, and firstly the surface of the silica nanoparticles is coated with a SiO2 coating to obtain a precursor Si@SiO2; then the surface of the precursor is coated with a PANI coating to obtain a compound material Si@SiO2@PANI; then the PANI is carbonized into porous carbon through calcining the compound material, a compound material Si@SiO2@NOC is obtained; finally SiO2 is removed through mechanical erosion with a hydrofluoric acid, and a compound material Si@SiO2@NOC is obtained to be the anode material for Li-ion batteries. According to the method, the discharged Anode material for Li-ion batteries can be charged, the problem of volume dilation of batteries is effectively solved, circulation property and rate property of batteries are improved; the preparation method is simple, and large scale production can be achieved.

10 citations

Patent
03 Nov 2017
TL;DR: In this article, a preparation method of a nitrogen-doped ordered carbon-coated silicon nanometer composite material is presented, which can serve as an excellent negative electrode material for lithium ion batteries.
Abstract: The invention discloses a preparation method of a nitrogen-doped ordered porous carbon coated silicon nanometer composite material. The preparation method comprises the following steps: firstly adopting dopamine hydrochloride coated silicon nanometer particles, then using cobaltous acetate for catalysis treatment, and finally carrying out high-temperature calcinations to obtain the target product. The preparation method of the composite material disclosed by the invention is simple, the obtained product is good in cycle stability and cycle specific capacity, and the composite material can serve as an excellent negative electrode material for lithium ion batteries.

4 citations

Patent
22 Feb 2017
TL;DR: In this paper, a flexible cathode material of a chargeable/dischargeable lithium-sulfur battery and a preparation method thereof was revealed. But the preparation method is simple, and an obtained product is the cathodes material having excellent battery performance.
Abstract: The invention discloses a flexible cathode material of a chargeable/dischargeable lithium-sulfur battery and a preparation method thereof. The method comprises: firstly, synthesizing polypyrrole nanofibers (PPy) by taking ammonium persulfate and pyrrole as raw materials; secondly, loading a positive active material namely elementary sulfur into the polypyrrole nanofibers to prepare a composite material (PPy/S); thirdly, performing extraction filtration in an order of graphene oxide-polypyrrole/sulfur-graphene oxide to obtain a GO-PPy/S-GO composite material having a sandwiched structure; finally, immersing the material into hydrofluoric acid, reducing the graphene oxide to graphene to obtain a graphene-polypyrrole/sulfur-graphene (G-PPy/S-G) composite material namely the cathode material. The composite material is obtained from conventional medicines by means of a layer-upon-layer extraction filtration method. The preparation method is simple, and an obtained product is the cathode material having excellent battery performance.

2 citations


Cited by
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Journal ArticleDOI
TL;DR: This work fabricates flexible, freestanding, and binder-free silicon/MXene composite papers directly as anodes for LIBs, a silicon-based anode candidate for lithium-ion batteries that exhibits superior electrochemical performance.
Abstract: Silicon has been developed as the exceptionally desirable anode candidate for lithium-ion batteries (LIBs), attributing to its highest theoretical capacity, low working potential, and abundant resource. However, large volume expansion and poor conductivity hinder its practical application. Herein, we fabricate flexible, freestanding, and binder-free silicon/MXene composite papers directly as anodes for LIBs. The Silicon/MXene composite papers are synthesized via covalently anchoring silicon nanospheres on the highly conductive networks based on MXene sheets by vacuum filtration. This unique architecture can accommodate large volume expansion, enhance conductivity of composites, prevent restacking of MXene sheets, offer additional active sites, and facilitate efficient ion transport, which exhibits superior electrochemical performance with a high capacity of 2118 mAh·g–1 at 200 mA·g–1 current density after 100 cycles, a steady cycling ability of 1672 mAh·g–1 at 1000 mA·g–1 after 200 cycles, and a rate perf...

214 citations

Journal ArticleDOI
TL;DR: The recent progress in the development of novel carbon nanostructures and carbon-derived energy storage devices is presented with particular emphasis on correlating the structures with electrochemical properties as well as assessing the device configuration, electrochemical reaction, and performance metric.
Abstract: The ever-increasing energy demand motivates the pursuit of inexpensive, safe, scalable, and high-performance rechargeable batteries. Carbon materials have been intensively investigated as electrode materials for various batteries on account of their resource abundance, low cost, nontoxicity, and diverse electrochemistry. Taking use of the reversible donor-type cation intercalation/de-intercalation (including Li+, Na+, and K+) at low redox potentials, carbon materials can serve as ideal anodes for 'Rocking-Chair' alkali metal-ion batteries. Meanwhile, acceptor-type intercalation of anions into graphitic carbon materials has also been revealed to be a facile, reversible process at high redox potentials. Based on anion-intercalation graphitic carbon materials, a number of dual-ion battery and Al-ion battery technologies are experiencing booming development. In this review, we summarize the significant advances of carbon materials in terms of the porous structure, chemical composition, and interlayer spacing control. Fundamental mechanisms of carbon materials as the cation host and anion host are further revisited by elaborating the electrochemistry, intercalant effect, and intercalation form. Subsequently, the recent progress in the development of novel carbon nanostructures and carbon-derived energy storage devices is presented with particular emphasis on correlating the structures with electrochemical properties as well as assessing the device configuration, electrochemical reaction, and performance metric. Finally, perspectives on the remaining challenges are provided, which will accelerate the development of new carbon material concepts and carbon-derived battery technologies towards commercial implementation.

180 citations

Journal ArticleDOI
TL;DR: Si/SiOx-DSHSs as discussed by the authors can facilitate the formation of a highly stable SEI layer and provide superior kinetics toward Li+ion storage, especially at high current density.
Abstract: Silicon (Si) is a promising anode candidate for lithium-ion batteries (LIBs) owing to its unprecedented theoretical capacity of 4200 mA h g−1 and earth-abundant supply (26.2 wt%). Nevertheless, the huge volume expansion and unstable solid-electrolyte interface (SEI) of Si in multiple cycles make it very hard to simultaneously achieve high-energy and long-term cycle life for applications in large-scale renewable energy storage. Herein, we demonstrate a new class of Si/SiOx@void@nitrogen-doped carbon double-shelled hollow superstructure (Si/SiOx-DSHS) electrodes that are capable of accommodating huge volume changes without pulverization during cycling. Benefiting from the unique double-shelled hollow superstructure, Si/SiOx-DSHSs can facilitate the formation of a highly stable SEI layer and provide superior kinetics toward Li+-ion storage. The diffusion-controlled process and the capacitance-type reaction can work together to endow Si/SiOx-DSHSs with remarkable electrochemical characteristics, especially at high current density. These important characteristics make Si/SiOx-DSHSs deliver a large reversible capacity (1290 mA h g−1 at 0.1C), high first-cycle coulombic efficiency (71.7%), superior rate capability (360 mA h g−1 at 10C), and excellent cycling behavior up to 1000 cycles with a small capacity decay of 10.2%. The Si/SiOx-DSHSs are among the best Si-based anode materials for LIBs reported to date.

111 citations

Journal ArticleDOI
TL;DR: InspInspired by the carbon nanotubes (CNTs) with high elasticity, the authors designed a flexible conductive Si/CNT composite where the CNTs are in situ grown in the porous Si particles with mesoscale porosity to solve the problems facing high capacity Si-based anodes.

101 citations