Rare earth ion （Nd^3＋/Y^3＋） and Al^3＋ codoped α-Ni（OH）2 powers were synthesized by chemical coprecipitation method. The structttre was analyzed with X-ray diffraction （XRD） and thermal gravity （TG）. Cyclic...Rare earth ion （Nd^3＋/Y^3＋） and Al^3＋ codoped α-Ni（OH）2 powers were synthesized by chemical coprecipitation method. The structttre was analyzed with X-ray diffraction （XRD） and thermal gravity （TG）. Cyclic voltammetry （CV） tests were performed to evaluate the proton diffusion coefficients of the samples. The results indicated that codoping of Y-Al and Nd-Al resulted in more water molecules contained within the crystal lattice and accordingly increased the interlayer spacing. In particular, the Y-Al codoped α-Ni（OH）2 showed a turbostratic structure. The calculated diffusion coefficients of the Y-Al codoped α-Ni（OH）2 and Nd-Al codoped α-Ni（OH）2 were 3.5×10^-10cm^2/s and 2.8× 10^-10 cm^2/s, respectively.展开更多
Al/Co co-doped α-Ni（OH）2 samples were prepared by either ultrasonic co-precipitation method （Sample B） or co-precipitation method （Sample A）. The crystal structure and particle size distribution of the prepared...Al/Co co-doped α-Ni（OH）2 samples were prepared by either ultrasonic co-precipitation method （Sample B） or co-precipitation method （Sample A）. The crystal structure and particle size distribution of the prepared samples were examined by X-ray diffraction （XRD） and laser particle size analyzer, respectively. The results show that Sample B has more crystalline defects and smaller average diameter than Sample A. The cyclic voltammetry and electrochemical impedance spectroscopy measurements indicate that Sample B has better electrochemical performance than Sample A, such as better reaction reversibility, lower charge-transfer resistance and better cyclic stability. Proton diffusion coefficient of Sample B is 1.96×10-10cm2/s, which is two times as large as that （9.78×10-11cm2/s） of Sample A. The charge-discharge tests show that the discharge capacity （308 mA·h/g） of Sample B is 25 mA·h/g higher than that of Sample A （283 mA·h/g）.展开更多
The additives-doped α-nickel hydroxides were prepared by supersonic co-precipitation method. The crystal structure and grain size of the prepared samples were characterized by X-ray diffraction （XRD） and Particle s...The additives-doped α-nickel hydroxides were prepared by supersonic co-precipitation method. The crystal structure and grain size of the prepared samples were characterized by X-ray diffraction （XRD） and Particle size distribution （PSD）, respectively. Cyclic voltammetry （CV） tests show that Al-Co-Y doped Ni（OH）2 has better reaction reversibility, higher proton diffusion coefficient than those of Al-Co doped Ni（OH）2. Al-Co-Y doped Ni（OH）2 also has lower charge-transfer resistance as shown by electrochemical impedance spectroscopy （EIS）. Charge/discharge tests show that the discharge capacity of Al-Co-Y doped Ni（OH）2 reaches 328 mAh/g at 0.2 C and 306 mAh/g at 0.5 C, while Al-Co doped Ni（OH）2 can only discharge a capacity of 308 mAh/g at 0.2 C and 267 mAh/g at 0.5 C.展开更多
There is considerable interest in using ionic liquids(ILs) as protic electrolytes. However, the reported proton transfer rate in ILs is quite slow. In this study, we report functionalizing imidazolium ILs with alcohol...There is considerable interest in using ionic liquids(ILs) as protic electrolytes. However, the reported proton transfer rate in ILs is quite slow. In this study, we report functionalizing imidazolium ILs with alcohol hydroxyls, aiming at constructing hydrogen bonding networks in the electrolyte, can stimulate fast proton hopping transfer. For demonstration, the diffusion of proton and Cl. in 1-(3-hydroxypropyl)-3-methylimidazolium tetrafluoroboride(C_3OHmimBF_4) were studied using cyclic voltammetry and potentiostatic method at 30 °C. The diffusion coefficient of proton is about one order of magnitude higher than that of Cl. in the same electrolyte, and about 5 times that of proton in the non-hydydroxyl 1-(butyl)-3-methylimidazolium tetrafluoroboride(BmimBF_4) when normalized to the diffusion coefficients of Cl. in respective ILs. In the meantime, 1H NMR spectra revealed a strong hydrogen bonding interaction between proton and C_3OHmimBF_4 which is absent between proton and BmimBF_4, thus the significantly higher diffusion coefficient of proton in C_3OHmimBF_4 may suggest the formation of effective hydrogen bonding networks, enabling rapid proton hopping via the Grotthuss mechanism.展开更多
基金the Guangxi Science Research and Technology Developing Foundation (0731001)
文摘Rare earth ion （Nd^3＋/Y^3＋） and Al^3＋ codoped α-Ni（OH）2 powers were synthesized by chemical coprecipitation method. The structttre was analyzed with X-ray diffraction （XRD） and thermal gravity （TG）. Cyclic voltammetry （CV） tests were performed to evaluate the proton diffusion coefficients of the samples. The results indicated that codoping of Y-Al and Nd-Al resulted in more water molecules contained within the crystal lattice and accordingly increased the interlayer spacing. In particular, the Y-Al codoped α-Ni（OH）2 showed a turbostratic structure. The calculated diffusion coefficients of the Y-Al codoped α-Ni（OH）2 and Nd-Al codoped α-Ni（OH）2 were 3.5×10^-10cm^2/s and 2.8× 10^-10 cm^2/s, respectively.
基金Project (10774030) supported by the National Natural Science Foundation of ChinaProject (2008J1-C161) supported by the Science and Technology Program of Guangzhou City of China
文摘Al/Co co-doped α-Ni（OH）2 samples were prepared by either ultrasonic co-precipitation method （Sample B） or co-precipitation method （Sample A）. The crystal structure and particle size distribution of the prepared samples were examined by X-ray diffraction （XRD） and laser particle size analyzer, respectively. The results show that Sample B has more crystalline defects and smaller average diameter than Sample A. The cyclic voltammetry and electrochemical impedance spectroscopy measurements indicate that Sample B has better electrochemical performance than Sample A, such as better reaction reversibility, lower charge-transfer resistance and better cyclic stability. Proton diffusion coefficient of Sample B is 1.96×10-10cm2/s, which is two times as large as that （9.78×10-11cm2/s） of Sample A. The charge-discharge tests show that the discharge capacity （308 mA·h/g） of Sample B is 25 mA·h/g higher than that of Sample A （283 mA·h/g）.
基金Funded by National Natural Science Foundation of China (No.10774030)Science and Technology Program of Guangzhou City of China (No.2008J1-C161)
文摘The additives-doped α-nickel hydroxides were prepared by supersonic co-precipitation method. The crystal structure and grain size of the prepared samples were characterized by X-ray diffraction （XRD） and Particle size distribution （PSD）, respectively. Cyclic voltammetry （CV） tests show that Al-Co-Y doped Ni（OH）2 has better reaction reversibility, higher proton diffusion coefficient than those of Al-Co doped Ni（OH）2. Al-Co-Y doped Ni（OH）2 also has lower charge-transfer resistance as shown by electrochemical impedance spectroscopy （EIS）. Charge/discharge tests show that the discharge capacity of Al-Co-Y doped Ni（OH）2 reaches 328 mAh/g at 0.2 C and 306 mAh/g at 0.5 C, while Al-Co doped Ni（OH）2 can only discharge a capacity of 308 mAh/g at 0.2 C and 267 mAh/g at 0.5 C.
基金supported by the National Natural Science Foundation of China(21173161,21673164)the Large-scale Instrument and Equipment Sharing Foundation of Wuhan University
文摘There is considerable interest in using ionic liquids(ILs) as protic electrolytes. However, the reported proton transfer rate in ILs is quite slow. In this study, we report functionalizing imidazolium ILs with alcohol hydroxyls, aiming at constructing hydrogen bonding networks in the electrolyte, can stimulate fast proton hopping transfer. For demonstration, the diffusion of proton and Cl. in 1-(3-hydroxypropyl)-3-methylimidazolium tetrafluoroboride(C_3OHmimBF_4) were studied using cyclic voltammetry and potentiostatic method at 30 °C. The diffusion coefficient of proton is about one order of magnitude higher than that of Cl. in the same electrolyte, and about 5 times that of proton in the non-hydydroxyl 1-(butyl)-3-methylimidazolium tetrafluoroboride(BmimBF_4) when normalized to the diffusion coefficients of Cl. in respective ILs. In the meantime, 1H NMR spectra revealed a strong hydrogen bonding interaction between proton and C_3OHmimBF_4 which is absent between proton and BmimBF_4, thus the significantly higher diffusion coefficient of proton in C_3OHmimBF_4 may suggest the formation of effective hydrogen bonding networks, enabling rapid proton hopping via the Grotthuss mechanism.
