Jiangyan Wang

Accurate Control of Multishelled Co3O4 Hollow Microspheres as High-Performance Anode Materials in Lithium-Ion Batteries

More than just an empty shell: Multishelled Co3O4 microspheres were synthesized as anode materials for lithium-ion batteries in high yield and purity. As their porous hollow multishell structure guarantees a shorter Li+ diffusion length and sufficient void space to buffer the volume expansion, their rate capacity, cycling performance, and specific capacity were excellent (1615.8 mA?h?g-1 in the 30th cycle for triple-shelled Co3O4; see graph).

Growth of Polypyrrole Ultrathin Films on MoS2 Monolayers as High-Performance Supercapacitor Electrodes

A scalable solution-based approach is developed to controllably grow PPy ultrathin films on 2D MoS2 monolayers. When these sandwiched nanocomposites are utilized as supercapacitor electrodes, a record high specific capacitance, remarkable rate capability, and improved cycling stability are achieved, offering a feasible solution to create the next generation of energy-storage device with superior power density and energy density.

Multishelled TiO2 hollow microspheres as anodes with superior reversible capacity for lithium ion batteries

Herein, uniform multishelled TiO2 hollow microspheres were synthesized, especially 3- and 4-shelled TiO2 hollow microspheres were synthesized for the first time by a simple sacrificial method capable of controlling the shell thickness, intershell spacing, and number of internal multishells, which are achieved by controlling the size, charge, and diffusion rate of the titanium coordination ions as well as the calcination process. Used as anodes for lithium ion batteries, the multishelled TiO2 hollow microspheres show excellent rate capacity, good cycling performance, and high specific capacity. A superior capacity, up to 237 mAh/g with minimal irreversible capacity after 100 cycles is achieved at a current rate of 1 C (167.5 mA/g), and a capacity of 119 mAh/g is achieved at a current rate of 10 C even after 1200 cycles.

Molecular Architecture of Cobalt Porphyrin Multilayers on Reduced Graphene Oxide Sheets for High-Performance Oxygen Reduction Reaction†

Thanks to their lightweight, highly efficient, modular and scalable properties, polymer electrolyte membrane fuel cells (PEMFCs) have long been thought to be a promising candidate for applications in transportation and in both stationary and portable electronics. [1] Unfortunately, despite the above advantages, until now the fuel-cell technologies have failed to reach mass commercialization, and the main problems include short operational time and high cost of the materials used. [1b–d] For example, platinum-based materials are generally believed to be ideal catalysts for the oxygen reduction reaction (ORR) at the cathodes of PEMFCs; however, their disadvantages, for example, low tolerance to methanol fuel, high price and scarcity, limit the practical application of platinum-based catalysts. [2] Therefore, replacement of platinum-based materials with non-precious-metal catalysts, which are of low cost, high catalytic activity, and robust, has become one of the key issues for the realization of mass applications of PEMFCs. [3a,b]

Quintuple-Shelled SnO2 Hollow Microspheres with Superior Light Scattering for High-Performance Dye-Sensitized Solar Cells

Quintuple-shelled SnO2 hollow microspheres are prepared by a hard-template method. DSSCs constructed with SnO2 multi-shell photoanodes show a record photoconversion efficiency of 7.18% due to enhanced light scattering. SnO2 hollow microspheres that are utilized as a scattering layer on top of P25 films increase the DSSC photoconversion efficiency from 7.29% to 9.53%.

Effects of morphine and its withdrawal on Y-maze spatial recognition memory in mice

UNLABELLED Effects of morphine on acquisition and retrieval of memory have been proven in the avoidance paradigms. In present study, we used a two-trial recognition Y-maze to test the effects of acute morphine and morphine withdrawal on spatial recognition memory. The Y-maze is based on the innate tendency of rodents to explore novel environments and therefore avoid punishment and reward. RESULTS 1) Pre-training morphine 10 mg/kg impaired the recognition spatial memory of acquisition after a 1 h inter-trial interval (ITI), whereas morphine 2.5, 5 and 10 mg/kg showed impairment after 2 h ITI. 2) Pre-retention morphine 5, 10 mg/kg disrupted the retrieval of memory after 1 h ITI. 3) Morphine 5 and 10 mg/kg caused hyper-locomotor activity depending on the state. 4) Mice withdrawn from morphine 40 mg/kg but not 10 mg/kg for 3 days showed amnesia in Y-maze. Our data suggested that acute morphine impaired the acquisition and retrieval of spatial recognition memory and increased the locomotor activity in the Y-maze depending on the dose and state. Moreover, withdrawal from chronic morphine also impaired acquisition in the Y-maze depending on the dose and state.

pH-Regulated Synthesis of Multi-Shelled Manganese Oxide Hollow Microspheres as Supercapacitor Electrodes Using Carbonaceous Microspheres as Templates

Multi‐shelled Mn2O3 hollow microspheres have been achieved through a pH‐regulated method and used as supercapacitor electrodes. The designed unique architecture allows efficient use of pseudo‐capacitive Mn2O3 nanomaterials for charge storage with facilitated transport for both ions and electrons, rendering them high specific capacitance, good rate capability, and remarkable cycling performance.

Multi-shelled LiMn2O4 hollow microspheres as superior cathode materials for lithium-ion batteries

Owing to its environmental-benignity, low-cost and abundance, spinel LiMn2O4 has long been considered as a promising cathode material for lithium-ion batteries (LIBs). However, the low electronic conductivity, small lithium diffusion coefficient and poor capacity retention hindered its further development and application. Herein, we report the synthesis of multi-shelled LiMn2O4 hollow microspheres through a hard template method, with the composition, shell number, shell thickness and porosity accurately controlled. Benefitting from the structural superiorities of multi-shelled hollow structures, the triple-shelled LiMn2O4 hollow microsphere exhibits a better cycling stability than all the reported results based on un-coated or un-doped LiMn2O4 (the capacity fading rate is 0.10% per cycle).

Engineering of multi-shelled SnO2 hollow microspheres for highly stable lithium-ion batteries

Uniform multi-shelled SnO2 hollow microspheres were synthesized through a sequential hard template method, and their electrochemical properties were investigated for their use as anodes for lithium-ion batteries. The multi-shelled SnO2 hollow electrode materials not only maintain a hierarchical structure during lithium ion insertion/extraction processes, but also improve the capacity of lithium-ion batteries.

Multi-shelled metal oxides prepared via an anion-adsorption mechanism for lithium-ion batteries

One of the major problems in the development of lithium-ion batteries is the relatively low capacity of cathode materials compared to anode materials. Owing to its high theoretical capacity, vanadium oxide is widely considered as an attractive cathode candidate. However, the main hindrances for its application in batteries are its poor capacity retention and low rate capability. Here, we report the development of multi-shelled vanadium oxide hollow microspheres and their related electrochemical properties. In contrast to the conventional cation-adsorption process, in which the metal cations adsorb on negatively charged carbonaceous templates, our approach enables the adsorption of metal anions. We demonstrate controlled syntheses of several multi-shelled metal oxide hollow microspheres. In particular, the multi-shelled vanadium oxide hollow microspheres deliver a specific capacity of 447.9 and 402.4mAhg(-1) for the first and 100th cycle at 1,000mAg(-1), respectively. The significant performance improvement offers the potential to reduce the wide capacity gap often seen between the cathode and anode materials.