scholarly journals Cobalt Sulfide Confined in N-Doped Porous Branched Carbon Nanotubes for Lithium-Ion Batteries

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Yongsheng Zhou ◽  
Yingchun Zhu ◽  
Bingshe Xu ◽  
Xueji Zhang ◽  
Khalid A. Al-Ghanim ◽  
...  

Abstract Lithium-ion batteries (LIBs) are considered new generation of large-scale energy-storage devices. However, LIBs suffer from a lack of desirable anode materials with excellent specific capacity and cycling stability. In this work, we design a novel hierarchical structure constructed by encapsulating cobalt sulfide nanowires within nitrogen-doped porous branched carbon nanotubes (NBNTs) for LIBs. The unique hierarchical Co9S8@NBNT electrode displayed a reversible specific capacity of 1310 mAh g−1 at a current density of 0.1 A g−1, and was able to maintain a stable reversible discharge capacity of 1109 mAh g−1 at a current density of 0.5 A g−1 with coulombic efficiency reaching almost 100% for 200 cycles. The excellent rate and cycling capabilities can be ascribed to the hierarchical porosity of the one-dimensional Co9S8@NBNT internetworks, the incorporation of nitrogen doping, and the carbon nanotube confinement of the active cobalt sulfide nanowires offering a proximate electron pathway for the isolated nanoparticles and shielding of the cobalt sulfide nanowires from pulverization over long cycling periods.

2021 ◽  
Author(s):  
Yuan Fang ◽  
Tengfei Li ◽  
Fen Wang ◽  
Jianfeng Zhu

Abstract Transition metal oxides as anode materials have received extensive research owing to the high specific capacity. Whereas, the rapid decline of battery capacity caused by volume expansion and low electrical conductivity hinders the practical application of transition metal oxides. This study reported a pseudo-capacitance material polypyrrole coated Fe2O3/Mn2O3 composites material as a high stability anode for lithium-ion batteries. The polypyrrole coating layer can not only serve as a conductive network to improve electrode conductivity but also can be used as a protective buffer layer to suppress the volume change of Fe2O3/Mn2O3 during the charging and discharging process. At the same time, the porous structure of Fe2O3/Mn2O3 composite can not only provide more active sites for lithium storage but also play a certain buffer effect on the volume change of the material. Polypyrrole-coated Fe2O3/Mn2O3 composite as the anode for lithium-ion batteries shows great electrochemical storage performance, with high specific capacity (627 mAh g− 1 at a current density of 1A g− 1), great cycle stability (the capacity not shows obvious signs of attenuation after 500 cycles) and rate performance (432 mAh g− 1 at a current density of 2.0 A g− 1).


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Manisha Phadatare ◽  
Rohan Patil ◽  
Nicklas Blomquist ◽  
Sven Forsberg ◽  
Jonas Örtegren ◽  
...  

Abstract To increase the energy storage density of lithium-ion batteries, silicon anodes have been explored due to their high capacity. One of the main challenges for silicon anodes are large volume variations during the lithiation processes. Recently, several high-performance schemes have been demonstrated with increased life cycles utilizing nanomaterials such as nanoparticles, nanowires, and thin films. However, a method that allows the large-scale production of silicon anodes remains to be demonstrated. Herein, we address this question by suggesting new scalable nanomaterial-based anodes. Si nanoparticles were grown on nanographite flakes by aerogel fabrication route from Si powder and nanographite mixture using polyvinyl alcohol (PVA). This silicon-nanographite aerogel electrode has stable specific capacity even at high current rates and exhibit good cyclic stability. The specific capacity is 455 mAh g−1 for 200th cycles with a coulombic efficiency of 97% at a current density 100 mA g−1.


2015 ◽  
Vol 3 (47) ◽  
pp. 24148-24154 ◽  
Author(s):  
Jieqiong Shan ◽  
Yuxin Liu ◽  
Ping Liu ◽  
Yanshan Huang ◽  
Yuezeng Su ◽  
...  

A dual-doping approach for N–C@SnO2–SnS/GN with 2D core–shell architecture has been developed. Used as the anode material in LIBs, it delivers a high specific capacity of 1236 mA h g−1 at a current density of 0.1 A g−1 after 110 cycles.


Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 569
Author(s):  
Liang Liu ◽  
Wei Dai ◽  
Hongzheng Zhu ◽  
Yanguang Gu ◽  
Kangkang Wang ◽  
...  

Silver vanadates (SVOs) have been widely investigated as cathode materials for high-performance lithium-ion batteries (LIBs). However, similar to most vanadium-based materials, SVOs suffer from structural collapse/amorphization and vanadium dissolution from the electrode into the electrolyte during the Li insertion and extraction process, causing poor electrochemical performance in LIBs. We employ ultrathin Al2O3 coatings to modify β-AgVO3 (as a typical example of SVOs) by an atomic layer deposition (ALD) technique. The galvanostatic charge-discharge test reveals that ALD Al2O3 coatings with different thicknesses greatly affected the cycling performance. Especially, the β-AgVO3 electrode with ~10 nm Al2O3 coating (100 ALD cycles) exhibits a high specific capacity of 271 mAh g−1, and capacity retention is 31%, much higher than the uncoated one of 10% after 100 cycles. The Coulombic efficiency is improved from 89.8% for the pristine β-AgVO3 to 98.2% for Al2O3-coated one. Postcycling analysis by cyclic voltammetry (CV), cyclic voltammetry (EIS), and scanning electron microscopy (SEM) disclose that 10-nm Al2O3 coating greatly reduces cathode-electrolyte interphase (CEI) resistance and the charge transfer resistance in the β-AgVO3 electrode. Al2O3 coating by the ALD method is a promising technique to construct artificial CEI and stabilize the structure of SVOs, providing new insights for vanadium-based electrodes and their energy storage devices.


Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 603 ◽  
Author(s):  
Yuxia Liu ◽  
Kai Jiang ◽  
Shuting Yang

A novel integrated electrode structure was designed and synthesized by direct electrodepositing of Cu–Sn alloy anode materials on the Celgard 2400 separator (Cel-CS electrode). The integrated structure of the Cel-CS electrode not only greatly simplifies the battery fabrication process and increases the energy density of the whole electrode, but also buffers the mechanical stress caused by volume expansion of Cu–Sn alloy active material; thus, effectively preventing active material falling off from the substrate and improving the cycle stability of the electrode. The Cel-CS electrode exhibits excellent cycle performance and superior rate performance. A capacity of 728 mA·h·g−1 can be achieved after 250 cycles at the current density of 100 mA·g−1. Even cycled at a current density of 5 A·g−1 for 650 cycles, the Cel-CS electrode maintained a specific capacity of 938 mA·h·g−1, which illustrates the potential application prospects of the Cel-CS electrode in microelectronic devices and systems.


2018 ◽  
Vol 11 (04) ◽  
pp. 1850067 ◽  
Author(s):  
Zheng Xing ◽  
Chunlai Huang ◽  
Yichen Deng ◽  
Yulong Zhao ◽  
Zhicheng Ju

A flexible strategy is to exploit encapsulating Si nanoparticles into N-doping carbon film (Si-NC) that can effectively localize the Si nanoparticles, thereby solving the problem of serious volume change during cycling as well as facilitating the fast diffusion of Li[Formula: see text], and thus achieving improved anode performance. A maximum capacity of 883.1[Formula: see text]mAh[Formula: see text]g[Formula: see text] at the current density of 100[Formula: see text]mA[Formula: see text]g[Formula: see text] after 50 charge and discharge processes is achieved for Si-NC. Even at a large current density of 2000[Formula: see text]mA[Formula: see text]g[Formula: see text], a specific capacity of 415[Formula: see text]mAh[Formula: see text]g[Formula: see text] is maintained. Moreover, the charge capacity can still almost recover the initial capacity as the current density is reverted to 100[Formula: see text]mA[Formula: see text]g[Formula: see text], indicating that Si-NC has a superior rate performance in lithium storage. This facile synthesis route provides a new perspective to produce Si/C composite at a low cost and large scale with good electrochemical performance.


2014 ◽  
Vol 1070-1072 ◽  
pp. 459-464
Author(s):  
Chang Jing Fu ◽  
Shuang Li ◽  
Qian Wang

Nitrogen-doped graphene (N-rGO) was synthesized in the process of preparation of reduced graphene oxide from the expanded graphite through the improved Hummers’ method. The morphology, structure and composition of nitrogen-doped graphene oxide (GO) and N-rGO were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The nitrogen content of N-rGO was approximately 5 at.%. The electrochemical performances of N-rGO as anode materials for lithium-ion batteries were evaluated in coin-type cells versus metallic lithium. Results showed that the obtained N-rGO exhibited a higher reversible specific capacity of 519 mAh g-1 at a current density of 100 mA⋅g-1 and 207.5 mAh⋅g-1 at a current density of 2000 mA⋅g-1. The excellent cycling stability and high-rate capability of N-rGO as anodes of lithium-ion battery were attributed to the large number of surface defects caused by the nitrogen doping, which facilitates the fast transport of Li-ion and electron on the interface of electrolyte/electrode.


2017 ◽  
Vol 8 ◽  
pp. 1297-1306 ◽  
Author(s):  
Jin Zhang ◽  
Yibing Cai ◽  
Xuebin Hou ◽  
Xiaofei Song ◽  
Pengfei Lv ◽  
...  

Titanium dioxide (TiO2) nanofibers have been widely applied in various fields including photocatalysis, energy storage and solar cells due to the advantages of low cost, high abundance and nontoxicity. However, the low conductivity of ions and bulk electrons hinder its rapid development in lithium-ion batteries (LIB). In order to improve the electrochemical performances of TiO2 nanomaterials as anode for LIB, hierarchically porous TiO2 nanofibers with different tetrabutyl titanate (TBT)/paraffin oil ratios were prepared as anode for LIB via a versatile single-nozzle microemulsion electrospinning (ME-ES) method followed by calcining. The experimental results indicated that TiO2 nanofibers with the higher TBT/paraffin oil ratio demonstrated more axially aligned channels and a larger specific surface area. Furthermore, they presented superior lithium-ion storage properties in terms of specific capacity, rate capability and cycling performance compared with solid TiO2 nanofibers for LIB. The initial discharge and charge capacity of porous TiO2 nanofibers with a TBT/paraffin oil ratio of 2.25 reached up to 634.72 and 390.42 mAh·g−1, thus resulting in a coulombic efficiency of 61.51%; and the discharge capacity maintained 264.56 mAh·g−1 after 100 cycles, which was much higher than that of solid TiO2 nanofibers. TiO2 nanofibers with TBT/paraffin oil ratio of 2.25 still obtained a high reversible capacity of 204.53 mAh·g−1 when current density returned back to 40 mA·g−1 after 60 cycles at increasing stepwise current density from 40 mA·g−1 to 800 mA·g−1. Herein, hierarchically porous TiO2 nanofibers have the potential to be applied as anode for lithium-ion batteries in practical applications.


RSC Advances ◽  
2015 ◽  
Vol 5 (10) ◽  
pp. 7356-7362 ◽  
Author(s):  
Minchan Li ◽  
Wenxi Wang ◽  
Mingyang Yang ◽  
Fucong Lv ◽  
Lujie Cao ◽  
...  

A novel microcuboid-shaped C–Fe3O4 assembly consisting of ultrafine nanoparticles derived from Fe–MOFs exhibits a greatly enhanced performance with high specific capacity, excellent cycling stability and good rate capability as anode materials for lithium ion batteries.


2017 ◽  
Vol 4 (12) ◽  
pp. 1996-2004 ◽  
Author(s):  
Yankai Li ◽  
Zhi Long ◽  
Pengyuan Xu ◽  
Yang Sun ◽  
Kai Song ◽  
...  

A novel silicon–carbon composite with a 3D pore-nest structure denoted as Si@SiOx/CNTs@C was prepared and studied, and the capacity of a Si@SiOx/CNTs@C composite anode can be maintained at above 1740 mA h g−1 at a current density of 0.42 A g−1 after 700 cycles.


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