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Yu F.,Shihezi University | Yu F.,Key Laboratory of Materials Oriented Chemical Engineering of Xinjiang Uygur Autonomous Region | Zhang L.,Institute of Chemical and Engineering Sciences, Singapore | Li Y.,Shihezi University | And 3 more authors.
RSC Advances | Year: 2014

Olivine-structured lithium ion phosphate (LiFePO4) is one of the most competitive candidates for fabricating energy-driven cathode material for sustainable lithium ion battery (LIB) systems. However, the high electrochemical performance is significantly limited by the slow diffusivity of Li-ion in LiFePO4 (ca. 10-14 cm2 s-1) together with the low electronic conductivity (ca. 10-9 S cm-1), which is the big challenge currently faced by us. To resolve the challenge, many efforts have been directed to the dynamics of the lithiation/delithiation process in LixFePO4 (0 ≤ x ≤ 1), mechanism of electrochemical modification, and synthetic reaction process, which are crucial for the development of high electrochemical performance for LiFePO4 material. In this review, in order to reflect the recent progress ranging from the very fundamental to practical applications, we specifically focus on the mechanism studies of LiFePO4 including the lithiation/delithiation process, electrochemical modification and synthetic reaction. Firstly, we highlight the Li-ion diffusion pathway in LixFePO4 and phase translation of LixFePO4. Then, we summarize the modification mechanism of LiFePO4 with high-rated capability, excellent low-temperature performance and high energy density. Finally, we discuss the synthetic reaction mechanism of high-temperature carbothermal reaction route and low-temperature hydrothermal/solvothermal reaction route. © the Partner Organisations 2014. Source

Peng J.,Shihezi University | Zuo Y.-T.,Shihezi University | Li G.,Shihezi University | Wang G.,Shihezi University | Wang G.,Key Laboratory of Materials Oriented Chemical Engineering of Xinjiang Uygur Autonomous Region
Chinese Chemical Letters | Year: 2016

A three-dimensional few-layer reduced graphene oxide-wrapped mesoporous Li4Ti5O12 (m-LTO@FL-RGO) electrode is produced using a simple solution fabrication process. When tested as an anode for Li-ion batteries, the m-LTO@FL-RGO composite exhibits excellent rate capability and superior cycle life. The capacity of m-LTO@FL-RGO reaches 165.4mAhg-1 after 100 cycles between 1 and 2.5V at a rate of 1C. Even at a rate of 30C, a high discharge capacity of 115.1mAhg-1 is still obtained, which is three times higher than the pristine mesoporous Li4Ti5O12 (m-LTO). The graphene nanosheets are incorporated into the m-LTO microspheres homogenously, which provide a high conductive network for electron transportation. © 2016 Gang Wang. Source

Zuo Y.-T.,Shihezi University | Peng J.,Shihezi University | Li G.,Shihezi University | Liu L.,Shihezi University | And 3 more authors.
Chinese Chemical Letters | Year: 2016

Hollow Fe3O4 (H-Fe3O4) microspheres were fabricated through a facile one-step solvothermal synthesis, which was performed in an ethylene glycol (EG)-diethylene glycol (DEG) mixed solvent using polyethylene glycol (PEG) as the stabilizer. The addition of DEG increased the viscosity of the system, which caused the Fe3O4 primary crystal to aggregate slower and the morphological yield to approach nearly 100%. The as-prepared hollow Fe3O4 microspheres show promise for application in lithium ion battery anodes and showed a reversible specific capacity of 453.3 mAh g-1 after 50 cycles at 100 mA g-1. © 2016 Chinese Chemical Society and Institute of Materia Medica. Source

Wang H.,Shihezi University | Wang H.,Key Laboratory of Materials Oriented Chemical Engineering of Xinjiang Uygur Autonomous Region | Wu C.,Shihezi University | Wei Z.,Shihezi University | And 2 more authors.
RSC Advances | Year: 2016

A novel and facile method to prepare surface chemistry, topology and separation performance controlled positively charged nanofiltration membranes by polydopamine-assisted grafting of starburst PAMAM onto polyethersulfone (PES) membranes was introduced. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM), zeta potential and water contact angle measurements were applied to characterize the morphology and chemical composition changes of the resultant membranes. The result of the salt rejections followed the sequence: R (MgCl2) > R (MgSO4) > R (NaCl) > R (Na2SO4), which indicated a PAMAM grafting membrane with a positively charged surface. The MgCl2 rejections of the resultant membrane increased with increasing PAMAM generation numbers (G0, G1 and G2) and reached 83.67%, 90.53% and 93.15%, respectively. The resultant membrane possessed a good structural stability and anti-fouling properties, which were determined by the long-term testing. This facile, mild and highly controllable polydopamine-assisted PAMAM grafting modification may find broad applicability in preparing positively charged NF membranes with tunable properties to meet potential needs. © The Royal Society of Chemistry 2016. Source

Li C.,Shihezi University | Wang H.,Shihezi University | Wang H.,Key Laboratory of Materials Oriented Chemical Engineering of Xinjiang Uygur Autonomous Region | Wu C.,Shihezi University | And 4 more authors.
Fibers and Polymers | Year: 2016

We introduced a novelty and mild method for preparing four different hydrophilic polymers (PVP, PAA, PDMAEMA, and PAM) grafted to DPVC fibrous membrane surface. To increase active sites and improve the grafting efficiency of hydrophilic polymer on PVC membrane, PVC resin was slightly dehydrochlorinated, forming a few conjugated double bonds. A minor reduction in the DPVC average molecular weight in a short dehydrochlorination time exerted minimal influence on the DPVC electrospinning process and fiber morphology. Results of ATR-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and surface wettability of modified membranes proved that hydrophilic polymers were successfully grafted covalently on the surface of the DPVC nanofibrous membrane. The hydrophilicity of the modified DPVC fibrous membrane was evidently improved. This hydrophilic DPVC fibrous membrane may fulfill potential requirements in tissue engineering and wastewater treatment. © 2016, The Korean Fiber Society and Springer Science+Business Media Dordrecht. Source

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