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1.
Songwei Gao Nü Wang Shuai Li Dianming Li Zhimin Cui Guichu Yue Jingchong Liu Xiaoxian Zhao Lei Jiang Yong Zhao 《Angewandte Chemie (International ed. in English)》2020,59(6):2465-2472
Multi‐wall Sn/SnO2@carbon hollow nanofibers evolved from SnO2 nanofibers are designed and programable synthesized by electrospinning, polypyrrole coating, and annealing reduction. The synthesized hollow nanofibers have a special wire‐in‐double‐wall‐tube structure with larger specific surface area and abundant inner spaces, which can provide effective contacting area of electrolyte with electrode materials and more active sites for redox reaction. It shows excellent cycling stability by virtue of effectively alleviating pulverization of tin‐based electrode materials caused by volume expansion. Even after 2000 cycles, the wire‐in‐double‐wall‐tube Sn/SnO2@carbon nanofibers exhibit a high specific capacity of 986.3 mAh g?1 (1 A g?1) and still maintains 508.2 mAh g?1 at high current density of 5 A g?1. This outstanding electrochemical performance suggests the multi‐wall Sn/SnO2@ carbon hollow nanofibers are great promising for high performance energy storage systems. 相似文献
2.
MnO2 Nanosheets Grown on Nitrogen‐Doped Hollow Carbon Shells as a High‐Performance Electrode for Asymmetric Supercapacitors
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Lei Li Rumin Li Shili Gai Prof. Shujiang Ding Fei He Prof. Milin Zhang Prof. Piaoping Yang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(19):7119-7126
A hierarchical hollow hybrid composite, namely, MnO2 nanosheets grown on nitrogen‐doped hollow carbon shells (NHCSs@MnO2), was synthesized by a facile in situ growth process followed by calcination. The composite has a high surface area (251 m2g?1) and mesopores (4.5 nm in diameter), which can efficiently facilitate transport during electrochemical cycling. Owing to the synergistic effect of NHCSs and MnO2, the composite shows a high specific capacitance of 306 F g?1, good rate capability, and an excellent cycling stability of 95.2 % after 5000 cycles at a high current density of 8 A g?1. More importantly, an asymmetric supercapacitor (ASC) assembled by using NHCSs@MnO2 and activated carbon as the positive and negative electrodes exhibits high specific capacitance (105.5 F g?1 at 0.5 A g?1 and 78.5 F g?1 at 10 A g?1) with excellent rate capability, achieves a maximum energy density of 43.9 Wh kg?1 at a power density of 408 W kg?1, and has high stability, whereby the ASC retains 81.4 % of its initial capacitance at a current density of 5 A g?1 after 4000 cycles. Therefore, the NHCSs@MnO2 electrode material is a promising candidate for future energy‐storage systems. 相似文献
3.
Formation of Triple‐Shelled Molybdenum–Polydopamine Hollow Spheres and Their Conversion into MoO2/Carbon Composite Hollow Spheres for Lithium‐Ion Batteries
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Dr. Yawen Wang Dr. Le Yu Prof. Xiong Wen Lou 《Angewandte Chemie (International ed. in English)》2016,55(47):14668-14672
Unique triple‐shelled Mo‐polydopamine (Mo‐PDA) hollow spheres are synthesized through a facile solvothermal process. A sequential self‐templating mechanism for the multi‐shell formation is proposed, and the number of shells can be adjusted by tuning the size of the Mo‐glycerate templates. These triple‐shelled Mo‐PDA hollow spheres can be converted to triple‐shelled MoO2/carbon composite hollow spheres by thermal treatment. Owing to the unique multi‐shells and hollow interior, the as‐prepared MoO2/carbon composite hollow spheres exhibit appealing performance as an anode material for lithium‐ion batteries, delivering a high capacity of ca. 580 mAh g?1 at 0.5 A g?1 with good rate capability and long cycle life. 相似文献
4.
Electrochemical Properties of Tin Oxide Flake/Reduced Graphene Oxide/Carbon Composite Powders as Anode Materials for Lithium‐Ion Batteries
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Su Min Lee Seung Ho Choi Prof. Yun Chan Kang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(46):15203-15207
Hierarchically structured tin oxide/reduced graphene oxide (RGO)/carbon composite powders are prepared through a one‐pot spray pyrolysis process. SnO nanoflakes of several hundred nanometers in diameter and a few nanometers in thickness are uniformly distributed over the micrometer‐sized spherical powder particles. The initial discharge and charge capacities of the tin oxide/RGO/carbon composite powders at a current density of 1000 mA g?1 are 1543 and 1060 mA h g?1, respectively. The discharge capacity of the tin oxide/RGO/carbon composite powders after 175 cycles is 844 mA h g?1, and the capacity retention measured from the second cycle is 80 %. The transformation during cycling of SnO nanoflakes, uniformly dispersed in the tin oxide/RGO/carbon composite powder, into ultrafine nanocrystals results in hollow nanovoids that act as buffers for the large volume changes that occur during cycling, thereby improving the cycling and rate performances of the tin oxide/RGO/carbon composite powders. 相似文献
5.
Nanostructured Carbon/Antimony Composites as Anode Materials for Lithium‐Ion Batteries with Long Life
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Dr. Yong Cheng Zheng Yi Dr. Chunli Wang Dr. Lidong Wang Prof. Yaoming Wu Prof. Limin Wang 《化学:亚洲杂志》2016,11(15):2173-2180
A series of nanostructured carbon/antimony composites have been successfully synthesized by a simple sol–gel, high‐temperature carbon thermal reduction process. In the carbon/antimony composites, antimony nanoparticles are homogeneously dispersed in the pyrolyzed nanoporous carbon matrix. As an anode material for lithium‐ion batteries, the C/Sb10 composite displays a high initial discharge capacity of 1214.6 mAh g?1 and a reversible charge capacity of 595.5 mAh g?1 with a corresponding coulombic efficiency of 49 % in the first cycle. In addition, it exhibits a high reversible discharge capacity of 466.2 mAh g?1 at a current density of 100 mA g?1 after 200 cycles and a high rate discharge capacity of 354.4 mAh g?1 at a current density of 1000 mA g?1. The excellent cycling stability and rate discharge performance of the C/Sb10 composite could be due to the uniform dispersion of antimony nanoparticles in the porous carbon matrix, which can buffer the volume expansion and maintain the integrity of the electrode during the charge–discharge cycles. 相似文献
6.
Wen Lu Junling Shen Peng Zhang Yijun Zhong Yong Hu Xiong Wen Lou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(43):15587-15593
Hierarchical hollow structures for electrode materials of supercapacitors could enlarge the surface area, accelerate the transport of ions and electrons, and accommodate volume expansion during cycling. Besides, construction of heterostructures would enhance the internal electric fields to regulate the electronic structures. All these features of hierarchical hollow heterostructures are beneficial for promoting the electrochemical properties and stability of electrode materials for high‐performance supercapacitors. Herein, CoO/Co‐Cu‐S hierarchical tubular heterostructures (HTHSs) composed of nanoneedles are prepared by an efficient multi‐step approach. The optimized sample exhibits a high specific capacity of 320 mAh g?1 (2300 F g?1) at 2.0 A g?1 and outstanding cycling stability with 96.5 % of the initial capacity retained after 5000 cycles at 10 A g?1. Moreover, an all‐solid‐state hybrid supercapacitor (HSC) constructed with the CoO/Co‐Cu‐S and actived carbon shows a stable and high energy density of 90.7 Wh kg?1 at a power density of 800 W kg?1. 相似文献
7.
High‐Loading Nano‐SnO2 Encapsulated in situ in Three‐Dimensional Rigid Porous Carbon for Superior Lithium‐Ion Batteries
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Hairong Xue Dr. Jianqing Zhao Jing Tang Hao Gong Prof. Ping He Prof. Haoshen Zhou Prof. Yusuke Yamauchi Prof. Jianping He 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(14):4915-4923
Tin oxide nanoparticles (SnO2 NPs) have been encapsulated in situ in a three‐dimensional ordered space structure. Within this composite, ordered mesoporous carbon (OMC) acts as a carbon framework showing a desirable ordered mesoporous structure with an average pore size (≈6 nm) and a high surface area (470.3 m2 g?1), and the SnO2 NPs (≈10 nm) are highly loaded (up to 80 wt %) and homogeneously distributed within the OMC matrix. As an anode material for lithium‐ion batteries, a SnO2@OMC composite material can deliver an initial charge capacity of 943 mAh g?1 and retain 68.9 % of the initial capacity after 50 cycles at a current density of 50 mA g?1, even exhibit a capacity of 503 mA h g?1 after 100 cycles at 160 mA g?1. In situ encapsulation of the SnO2 NPs within an OMC framework contributes to a higher capacity and a better cycling stability and rate capability in comparison with bare OMC and OMC ex situ loaded with SnO2 particles (SnO2/OMC). The significantly improved electrochemical performance of the SnO2@OMC composite can be attributed to the multifunctional OMC matrix, which can facilitate electrolyte infiltration, accelerate charge transfer, and lithium‐ion diffusion, and act as a favorable buffer to release reaction strains for lithiation/delithiation of the SnO2 NPs. 相似文献
8.
Synthesis of Hierarchically Porous Sandwich‐Like Carbon Materials for High‐Performance Supercapacitors
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Yiju Li Dr. Chaoji Chen Tingting Gao Dr. Dongming Zhang Dr. Xiaomei Huang Yue Pan Dr. Ke Ye Dr. Kui Cheng Dr. Dianxue Cao Dr. Guiling Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(47):16863-16871
For the first time, hierarchically porous carbon materials with a sandwich‐like structure are synthesized through a facile and efficient tri‐template approach. The hierarchically porous microstructures consist of abundant macropores and numerous micropores embedded into the crosslinked mesoporous walls. As a result, the obtained carbon material with a unique sandwich‐like structure has a relatively high specific surface (1235 m2 g?1), large pore volume (1.30 cm3 g?1), and appropriate pore size distribution. These merits lead to a comparably high specific capacitance of 274.8 F g?1 at 0.2 A g?1 and satisfying rate performance (87.7 % retention from 1 to 20 A g?1). More importantly, the symmetric supercapacitor with two identical as‐prepared carbon samples shows a superior energy density of 18.47 Wh kg?1 at a power density of 179.9 W kg?1. The asymmetric supercapacitor based on as‐obtained carbon sample and its composite with manganese dioxide (MnO2) can reach up to an energy density of 25.93 Wh kg?1 at a power density of 199.9 W kg?1. Therefore, these unique carbon material open a promising prospect for future development and utilization in the field of energy storage. 相似文献
9.
Nitrogen‐Doped Hollow Amorphous Carbon Spheres@Graphitic Shells Derived from Pitch: New Structure Leads to Robust Lithium Storage
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Qingtao Ma Prof. Dr. Luxiang Wang Dr. Wei Xia Prof. Dr. Dianzeng Jia Prof. Zongbin Zhao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(7):2339-2344
Nitrogen‐doped mesoporous hollow carbon spheres (NHCS) consisting of hybridized amorphous and graphitic carbon were synthesized by chemical vapor deposition with pitch as raw material. Treatment with HNO3 vapor was performed to incorporate oxygen‐containing groups on NHCS, and the resulting NHCS‐O showed excellent rate capacity, high reversible capacity, and excellent cycling stability when tested as the anode material in lithium‐ion batteries. The NHCS‐O electrode maintained a reversible specific capacity of 616 mAh g?1 after 250 cycles at a current rate of 500 mA g?1, which is an increase of 113 % compared to the pristine hollow carbon spheres. In addition, the NHCS‐O electrode exhibited a reversible capacity of 503 mAh g?1 at a high current density of 1.5 A g?1. The superior electrochemical performance of NHCS‐O can be attributed to the hybrid structure, high N and O contents, and rich surface defects. 相似文献
10.
Songwei Gao Dr. Nü Wang Shuai Li Dianming Li Dr. Zhimin Cui Guichu Yue Jingchong Liu Prof. Xiaoxian Zhao Prof. Lei Jiang Prof. Yong Zhao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(6):2486-2493
Multi-wall Sn/SnO2@carbon hollow nanofibers evolved from SnO2 nanofibers are designed and programable synthesized by electrospinning, polypyrrole coating, and annealing reduction. The synthesized hollow nanofibers have a special wire-in-double-wall-tube structure with larger specific surface area and abundant inner spaces, which can provide effective contacting area of electrolyte with electrode materials and more active sites for redox reaction. It shows excellent cycling stability by virtue of effectively alleviating pulverization of tin-based electrode materials caused by volume expansion. Even after 2000 cycles, the wire-in-double-wall-tube Sn/SnO2@carbon nanofibers exhibit a high specific capacity of 986.3 mAh g−1 (1 A g−1) and still maintains 508.2 mAh g−1 at high current density of 5 A g−1. This outstanding electrochemical performance suggests the multi-wall Sn/SnO2@ carbon hollow nanofibers are great promising for high performance energy storage systems. 相似文献
11.
Facile Mechanochemical Synthesis of Nano SnO2/Graphene Composite from Coarse Metallic Sn and Graphite Oxide: An Outstanding Anode Material for Lithium‐Ion Batteries
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Fei Ye Bote Zhao Prof. Ran Ran Prof. Zongping Shao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(14):4055-4063
A facile method for the large‐scale synthesis of SnO2 nanocrystal/graphene composites by using coarse metallic Sn particles and cheap graphite oxide (GO) as raw materials is demonstrated. This method uses simple ball milling to realize a mechanochemical reaction between Sn particles and GO. After the reaction, the initial coarse Sn particles with sizes of 3–30 μm are converted to SnO2 nanocrystals (approximately 4 nm) while GO is reduced to graphene. Composite with different grinding times (1 h 20 min, 2 h 20 min or 8 h 20 min, abbreviated to 1, 2 or 8 h below) and raw material ratios (Sn:GO, 1:2, 1:1, 2:1, w/w) are investigated by X‐ray diffraction, X‐ray photoelectron spectroscopy, field‐emission scanning electron microscopy and transmission electron microscopy. The as‐prepared SnO2/graphene composite with a grinding time of 8 h and raw material ratio of 1:1 forms micrometer‐sized architected chips composed of composite sheets, and demonstrates a high tap density of 1.53 g cm?3. By using such composites as anode material for LIBs, a high specific capacity of 891 mA h g?1 is achieved even after 50 cycles at 100 mA g?1. 相似文献
12.
Rational Design of Ni Nanoparticles on N‐Rich Ultrathin Carbon Nanosheets for High‐Performance Supercapacitor Materials: Embedded‐ Versus Anchored‐Type Dispersion
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Mei Yang Yiren Zhong Dr. Liwei Su Prof. Jinping Wei Prof. Zhen Zhou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(17):5046-5053
Highly dispersed Ni nanoparticles (NPs) and abundant functional N‐species were integrated into ultrathin carbon nanosheets by using a facile and economical sol–gel route. Embedded‐ and anchored‐type configurations were achieved for the dispersion of Ni NPs in/on N‐rich carbon nanosheets. The anchored‐type composite exhibited outstanding pseudocapacitance of 2200 F g?1 at 5 A g?1 with unusual rate capability and extraordinary cyclic stability over 20 000 cycles with little capacitance decay. Aqueous asymmetric supercapacitors fabricated with this composite cathode demonstrated a high energy density of 51.3 Wh kg?1 at a relatively large power density of 421.6 W kg?1, along with outstanding cyclic stability. This approach opens an attractive direction for enhancing the electrochemical performances of metal‐based supercapacitors and can be generalized to design high‐performance energy‐storage devices. 相似文献
13.
Facile Synthesis of A 3D Flower‐Like Mesoporous Ni@C Composite Material for High‐Energy Aqueous Asymmetric Supercapacitors
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Dr. Song Liu Dr. Cuihua An Dr. Lei Zang Xiaoya Chang Huinan Guo Prof. Dr. Lifang Jiao Prof. Dr. Yijing Wang 《化学:亚洲杂志》2018,13(8):1005-1011
A 3D flower‐like mesoporous Ni@C composite material has been synthesized by using a facile and economical one‐pot hydrothermal method. This unique 3D flower‐like Ni@C composite, which exhibited a high surface area (522.4 m2 g?1), consisted of highly dispersed Ni nanoparticles on mesoporous carbon flakes. The effect of calcination temperature on the electrochemical performance of the Ni@C composite was systematically investigated. The optimized material (Ni@C 700) displayed high specific capacity (1306 F g?1 at 2 A g?1) and excellent cycling performance (96.7 % retention after 5000 cycles). Furthermore, an asymmetric supercapacitor (ASC) that contained Ni@C 700 as cathode and mesoporous carbon (MC) as anode demonstrated high energy density (60.4 W h kg?1 at a power density of 750 W kg?1). 相似文献
14.
Guiyin Xu Bing Ding Ping Nie Laifa Shen Jie Wang Prof. Xiaogang Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(37):12306-12312
Porous nitrogen‐doped carbon nanotubes (PNCNTs) with a high specific surface area (1765 m2 g?1) and a large pore volume (1.28 cm3 g?1) have been synthesized from a tubular polypyrrole (T‐PPY). The inner diameter and wall thickness of the PNCNTs are about 55 nm and 22 nm, respectively. This material shows extremely promising properties for both supercapacitors and for encapsulating sulfur as a superior cathode material for high‐performance lithium–sulfur (Li‐S) batteries. At a current density of 0.5 A g?1, PNCNT presents a high specific capacitance of 210 F g?1, as well as excellent cycling stability at a current density of 2 A g?1. When the S/PNCNT composite was tested as the cathode material for Li‐S batteries, the initial discharge capacity was 1341 mAh g?1 at a current rate of 1 C and, even after 50 cycles at the same rate, the high reversible capacity was retained at 933 mAh g?1. The promising electrochemical energy‐storage performance of the PNCNTs can be attributed to their excellent conductivity, large surface area, nitrogen doping, and unique pore‐size distribution. 相似文献
15.
Erbo Cheng Shoushuang Huang Dayong Chen Ruting Huang Qing Wang Zhangjun Hu Yong Jiang Zhen Li Bing Zhao Zhiwen Chen 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(7):969-978
Metal oxides have a large storage capacity when employed as anode materials for lithium‐ion batteries (LIBs). However, they often suffer from poor capacity retention due to their low electrical conductivity and huge volume variation during the charge–discharge process. To overcome these limitations, fabrication of metal oxides/carbon hybrids with hollow structures can be expected to further improve their electrochemical properties. Herein, ZnO‐Co3O4 nanocomposites embedded in N‐doped carbon (ZnO‐Co3O4@N‐C) nanocages with hollow dodecahedral shapes have been prepared successfully by the simple carbonizing and oxidizing of metal–organic frameworks (MOFs). Benefiting from the advantages of the structural features, i.e. the conductive N‐doped carbon coating, the porous structure of the nanocages and the synergistic effects of different components, the as‐prepared ZnO‐Co3O4@N‐C not only avoids particle aggregation and nanostructure cracking but also facilitates the transport of ions and electrons. As a result, the resultant ZnO‐Co3O4@N‐C shows a discharge capacity of 2373 mAh g?1 at the first cycle and exhibits a retention capacity of 1305 mAh g?1 even after 300 cycles at 0.1 A g?1. In addition, a reversible capacity of 948 mAh g?1 is obtained at a current density of 2 A g?1, which delivers an excellent high‐rate cycle ability. 相似文献
16.
Electrochemical Properties of Hollow‐Structured MnS–Carbon Nanocomposite Powders Prepared by a One‐Pot Spray Pyrolysis Process
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Spherical, hollow MnS? C composite powders were prepared from a solution of manganese salt, thiourea, and sucrose by one‐pot spray pyrolysis. The MnS? C composite powders were generated by direct sulfidation of MnO with hydrogen sulfide gas generated in situ by decomposition of thiourea during spray pyrolysis. Sucrose, which is used as a carbon source material, plays a key role in the formation of the MnS? C composite powders by improving the reducing atmosphere around the powders. Dot‐mapping images of the composite powders demonstrated uniform distribution of the manganese, sulfur, and carbon components within the MnS? C composite powder. Fine crystals of MnS were uniformly mixed with carbon derived from polymerization and carbonization of sucrose. The carbon content of the MnS? C composite powders was 26 wt %. The discharge capacities of the MnS? C composite powders in the 2nd and 200th cycles were 863 and 967 mA h g?1, respectively, at a current density of 1000 mA g?1. The spherical and hollow morphology of the MnS? C composite powders was completely retained, even after 200 cycles. The enhanced cycling and rate performance of the MnS? C composite powders is ascribed to the structural stability of the composite powders. 相似文献
17.
Excellent Capacitive Performance of a Three‐Dimensional Hierarchical Porous Graphene/Carbon Composite with a Superhigh Surface Area
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Xue Jin Li Prof. Wei Xing Prof. Jin Zhou Prof. Gui Qiang Wang Prof. Shu Ping Zhuo Prof. Zi Feng Yan Prof. Qing Zhong Xue Prof. Shi Zhang Qiao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(41):13314-13320
Three‐dimensional hierarchical porous graphene/carbon composite was successfully synthesized from a solution of graphene oxide and a phenolic resin by using a facile and efficient method. The morphology, structure, and surface property of the composite were investigated intensively by a variety of means such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption, Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). It is found that graphene serves as a scaffold to form a hierarchical pore texture in the composite, resulting in its superhigh surface area of 2034 m2g?1, thin macropore wall, and high conductivity (152 S m?1). As evidenced by electrochemical measurements in both EMImBF4 ionic liquid and KOH electrolyte, the composite exhibits ideal capacitive behavior, high capacitance, and excellent rate performance due to its unique structure. In EMImBF4, the composite has a high energy density of up to 50.1 Wh kg?1 and also possesses quite stable cycling stability at 100 °C, suggesting its promising application in high‐temperature supercapacitors. In KOH electrolyte, the specific capacitance of this composite can reach up to an unprecedented value of 186.5 F g?1, even at a very high current density of 50 A g?1, suggesting its prosperous application in high‐power applications. 相似文献
18.
Dr. Anqiang Pan Ting Zhu Hao Bin Wu Prof. Xiong Wen Lou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(2):494-500
Nanosheet‐assembled hierarchical V2O5 hollow microspheres are successfully obtained from V‐glycolate precursor hollow microspheres, which in turn are synthesized by a simple template‐free solvothermal method. The structural evolution of the V‐glycolate hollow microspheres has been studied and explained by the inside‐out Ostwald‐ripening mechanism. The surface morphologies of the hollow microspheres can be controlled by varying the mixture solution and the solvothermal reaction time. After calcination in air, hierarchical V2O5 hollow microspheres with a high surface area of 70 m2 g?1 can be obtained and the structure is well preserved. When evaluated as cathode materials for lithium‐ion batteries, the as‐prepared hierarchical V2O5 hollow spheres deliver a specific discharge capacity of 144 mA h g?1 at a current density of 100 mA g?1, which is very close to the theoretical capacity (147 mA h g?1) for one Li+ insertion per V2O5. In addition, excellent rate capability and cycling stability are observed, suggesting their promising use in lithium‐ion batteries. 相似文献
19.
Lei Zhang Chengrui Wang Yuhai Dou Ningyan Cheng Dandan Cui Yi Du Porun Liu Mohammad Al‐Mamun Shanqing Zhang Huijun Zhao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(26):8916-8920
The poor cycling stability resulting from the large volume expansion caused by lithiation is a critical issue for Si‐based anodes. Herein, we report for the first time of a new yolk–shell structured high tap density composite made of a carbon‐coated rigid SiO2 outer shell to confine multiple Si NPs (yolks) and carbon nanotubes (CNTs) with embedded Fe2O3 nanoparticles (NPs). The high tap density achieved and superior conductivity can be attributed to the efficiently utilised inner void containing multiple Si yolks, Fe2O3 NPs, and CNTs Li+ storage materials, and the bridged spaces between the inner Si yolks and outer shell through a conductive CNTs “highway”. Half cells can achieve a high area capacity of 3.6 mAh cm?2 and 95 % reversible capacity retention after 450 cycles. The full cell constructed using a Li‐rich Li2V2O5 cathode can achieve a high reversible capacity of 260 mAh g?1 after 300 cycles. 相似文献
20.
Superior Lithium‐Ion Storage Properties of Mesoporous CuO–Reduced Graphene Oxide Composite Powder Prepared by a Two‐Step Spray‐Drying Process
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Gi Dae Park Prof. Yun Chan Kang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(25):9179-9184
Mesoporous CuO–reduced graphene oxide (rGO) composite powders were prepared by using a two‐step spray‐drying process. In the first step, hollow CuO powders were prepared from a spray solution of copper nitrate trihydrate with citric acid and were wet milled to obtain a colloidal spray solution. In the second step, spray drying of the colloidal solution that contained dispersed GO nanosheets produced mesoporous CuO–rGO composite powders with particle sizes of several microns. Thermal reduction of GO nanosheets to rGO nanosheets occurred during post‐treatment at 300 °C. Initial discharge capacities of the hollow CuO, bare CuO aggregate, and CuO–rGO composite powders at a current density of 2 A g?1 were 838, 1145, and 1238 mA h g?1, respectively. Their discharge capacities after 200 cycles were 259, 380, and 676 mA h g?1, respectively, and their corresponding capacity retentions measured from the second cycle were 67, 48, and 76 %, respectively. The mesoporous CuO–rGO composite powders have high structural stability and high conductivity because of the rGO nanosheets, and display good cycling and rate performances. 相似文献