Entity

Time filter

Source Type


Luo Y.,Wuhan University of Technology | Xu X.,Wuhan University of Technology | Xu X.,University of California at Los Angeles | Zhang Y.,WUT Powerful Energy Co. | And 6 more authors.
ACS Applied Materials and Interfaces | Year: 2016

Hierarchical Co2V2O7 nanosheets consisted of interconnected nanoparticles are synthesized by a facile method using graphene oxide as the template. The electrochemical reaction mechanism of the Co2V2O7 nanosheets is thoroughly investigated by in situ XRD and ex situ TEM. The initial Co2V2O7 transforms into CoO nanoparticles and vanadium oxides in the first cycle, and the following reversible conversion reaction mainly occurs between CoO and Co and lithiation/delithiation of the vanadium oxides. The Co2V2O7 nanosheet displays a high reversible capacity (962 mAh/g at 0.5 A/g) and remarkable high rate capability. When cycled at 5.0 A/g, a reversible capacity of 441 mAh/g can be retained after 900 cycles. The stable high capacity and excellent rate capability make the hierarchical Co2V2O7 nanosheets a promising anode material for lithium-ion batteries. © 2016 American Chemical Society. Source


Luo Y.,Wuhan University of Technology | Xu X.,Wuhan University of Technology | Zhang Y.,WUT Powerful Energy Co. | Pi Y.,WUT Powerful Energy Co. | And 5 more authors.
Advanced Energy Materials | Year: 2014

Developing rechargeable lithium ion batteries with fast charge/discharge rate, high capacity and power, long lifespan, and broad temperature adaptability is still a significant challenge. In order to realize the fast and efficient transport of ions and electrons during the charging/discharging process, a 3D hierarchical carbon-decorated Li3V2(PO4)3 is designed and synthesized with a nanoscale amorphous carbon coating and a microscale carbon network. The Brunauer-Emmett-Teller (BET) surface area is 65.4 m2 g-1 and the porosity allows for easy access of the electrolyte to the active material. A specific capacity of 121 mAh g-1 (91% of the theoretical capacity) can be obtained at a rate up to 30 C. When cycled at a rate of 20 C, the capacity retention is 77% after 4000 cycles, corresponding to a capacity fading of 0.0065% per cycle. More importantly, the composite cathode shows excellent temperature adaptability. The specific discharge capacities can reach 130 mAh g-1 at 20 C and 60 °C, and 106 mAh g-1 at 5 C and -20 °C. The rate performance and broad temperature adaptability demonstrate that this hierarchical carbon-decorated Li3V2(PO4)3 is one of the most attractive cathodes for practical applications. A 3D hierarchical carbon decorated Li3V2(PO4)3 cathode material provides continuous electron conduction, rapid ion transport, and a buffered protective carbon shell of the active material particles. It delivers desirable discharge capacity and can be cycled for 4000 times with minimal capacity loss at a high rate. The excellent temperature adaptability also indicates its superiority in practical applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Luo Y.,Wuhan University of Technology | Xu X.,Wuhan University of Technology | Zhang Y.,WUT Powerful Energy Co. | Pi Y.,WUT Powerful Energy Co. | And 4 more authors.
ACS Applied Materials and Interfaces | Year: 2015

Olivine-type LiMnPO4 has been extensively studied as a high-energy density cathode material for lithium-ion batteries. To improve both the ionic and electronic conductivities of LiMnPO4, a series of carbon-decorated LiMnPO4·Li3V2(PO4)3 nanocomposites are synthesized by a facile sol-gel method combined with the conventional solid-state method. The optimized composite presents a three-dimensional hierarchical structure with active nanoparticles well-embedded in a conductive carbon matrix. The combination of the nanoscale carbon coating and the microscale carbon network could provide a more active site for electrochemical reaction, as well as a highly conductive network for both electron and lithium-ion transportation. When cycled at 20 C, an initial specific capacity of 103 mA h g-1 can be obtained and the capacity retention reaches 68% after 3000 cycles, corresponding to a capacity fading of 0.013% per cycle. The stable capacity and excellent rate capability make this carbon-decorated LiMnPO4·Li3V2(PO4)3 nanocomposite a promising cathode for lithium-ion batteries. © 2015 American Chemical Society. Source

Discover hidden collaborations