A new design route was presented to fabricate cobalt aluminum-layered double hydroxide(CoAl-LDH)thin layers whichgrow on carbon spheres(CSs)through a growth method.The CoAl-LDH thin layers consist of nanoflakes with a...A new design route was presented to fabricate cobalt aluminum-layered double hydroxide(CoAl-LDH)thin layers whichgrow on carbon spheres(CSs)through a growth method.The CoAl-LDH thin layers consist of nanoflakes with a thickness of20nm.The galvanostatic charge-discharge test of the CoAl-LDH/CSs composite shows a great specific capacitance of1198F/g at1A/g(based on the mass of the CoAl-LDH/CSs composite)in6mol/L KOH solution,and the composite displays an impressive specificcapacitance of920F/g even at a high current density of10A/g.Moreover,the composite remains a specific capacitance of928F/gafter1000cycles at2A/g,and the specific capacitance retention is84%,indicating that the composite has high specific capacitance,excellent rate capability and good cycling stability in comparison to pristine CoAl-LDH.展开更多
Lithium-aluminum layered double hydroxides(LiAl-LDH)have been be successfully applied in commercial-scale for lithium extraction from salt lake brine,however,further advancement of their applications is hampered by su...Lithium-aluminum layered double hydroxides(LiAl-LDH)have been be successfully applied in commercial-scale for lithium extraction from salt lake brine,however,further advancement of their applications is hampered by suboptimal Li^(+)adsorption performance and ambiguous extraction process.Herein,a doping engineering strategy was developed to fabricate novel Zn^(2+)-doped LiAl-LDH(LiZnAl-LDH)with remarkable higher Li^(+)adsorption capacity(13.4 mg/g)and selectivity(separation factors of 213,834,171 for Li^(+)/K^(+),Li^(+)/Na^(+),Li^(+)/Mg^(2+),respectively),as well as lossless reusability in Luobupo brine compared to the pristine LiAl-LDH.Further,combining experiments and simulation calculations,it was revealed that the specific surface area,hydrophilic,and surface attraction for Li^(+)of LiZnAl-LDH were significantly improved,reducing the adsorption energy(Ead)and Gibbs free energy(ΔG),thus facilitating the transfer of Li^(+)from brine into interface followed by insertion into voids.Importantly,the intrinsic oxygen vacancies derived from Zn-doping depressed the diffusion energy barrier of Li^(+),which accelerated the diffusion process of Li^(+)in the internal bulk of LiZnAl-LDH.This work provides a general strategy to overcome the existing limitations of Li^(+)recovery and deepens the understanding of Li^(+)extraction on LiAl-LDH.展开更多
With the growing concerns on global energy crisis and the greenhouse effect,the exploration on renewable energy and related emerging energy conversion and storage technologies are highly interested [1].Lithium sulfur ...With the growing concerns on global energy crisis and the greenhouse effect,the exploration on renewable energy and related emerging energy conversion and storage technologies are highly interested [1].Lithium sulfur (Li–S) battery system receives great attention for its high theoretical specific energy(2600 Wh/kg),which is deemed to be a promising candidate as next generation high energy density batteries [2].展开更多
<span style="font-family:Verdana;"> <span style="font-family:;" "="">LDH-phases become increasingly interesting due to their broad ability to be able to incorporate many ...<span style="font-family:Verdana;"> <span style="font-family:;" "="">LDH-phases become increasingly interesting due to their broad ability to be able to incorporate many different cat</span><span style="font-family:;" "="">ions</span><span style="font-family:;" "=""> and anions. The intercalation of methanesulfonate and ethanesulfonate into a Li-LDH as well as the behavior of the interlayer structure as a function of the temperature is presented. A hexagonal P6<sub>3</sub>/m [LiAl<sub>2</sub>(OH)<sub>6</sub>][Cl?1</span><span style="font-family:;" "="">.</span><span style="font-family:;" "="">5H<sub>2</sub>O] (Li-Al-Cl) precursor LDH was synthesized by hydrothermal treating of a LiCl solution with <i>γ</i>-Al(OH)<sub>3</sub>. This precursor was used to intercalate methanesulfonate (CH<sub>3</sub>O<sub>3</sub>S<sup>?</sup>) and ethanesulfonate (C<sub>2</sub>H<sub>5</sub>O<sub>3</sub>S<sup>?</sup>) through anion exchange by stirring Li-Al-Cl in a solution of the respective organic Li-salt (90?C, 12 h). X-ray diffraction pattern showed an increase of the interlayer space <i>c</i></span><i><span style="font-family:;" "="">'</span></i><span style="font-family:;" "=""> (d<sub>001</sub>) of Li-Al-methanesulfonate (Li-Al-MS) with 1.2886 nm and Li-Al-ethanesulfonate (Li-Al-ES) with 1.3816 nm compared to the precursor with 0.7630 nm. Further investigations with Fourier-transform infrared spectroscopy and scanning electron microscopy confirmed a complete anion exchange of the organic molecules with the precursor Cl<sup>?</sup>. Both synthesized LDH compounds [LiAl<sub>2</sub>(OH)<sub>6</sub>]CH<sub>3</sub>SO<sub>3</sub>?nH<sub>2</sub>O (n = 2.24</span><span style="font-family:;" "="">-</span><span style="font-family:;" "="">3.72 (Li-Al-MS) and [LiAl<sub>2</sub>(OH)<sub>6</sub>]C<sub>2</sub>H<sub>5</sub>SO<sub>3</sub>}?nH<sub>2</sub>O (n = 1.5) (Li-Al-ES) showed a monomolecular interlayer structure with additional interlayer water at room temperature. By increasing the temperature, the interlayer water was removed and the interlayer space <i>c</i></span><i><span style="font-family:;" "="">'</span></i><span style="font-family:;" "=""> of Li-Al-MS decreased to 0.87735 nm (at 55?C). Calculations showed that a slight displacement of the organic molecules is necessary to achieve this interlayer space. Different behavior of Li-Al-ES could be observed during thermal treatment. Two phases coexisted at 75?C </span><span style="font-family:;" "="">-</span><span style="font-family:;" "=""> 85?C, one with a reduced <i>c</i></span><i><span style="font-family:;" "="">'</span></i><span style="font-family:;" "=""> (0.9015 nm, 75?C) and one with increased <i>c</i></span><i><span style="font-family:;" "="">'</span></i><span style="font-family:;" "=""> (1.5643 nm, 85?C) compared to the LDH compound at room temperature. The increase of <i>c</i></span><i><span style="font-family:;" "="">'</span></i><span style="font-family:;" "=""> is due to the formation of a bimolecular interlayer structure.</span><span style="font-family:;" "=""></span> <p> <br /> </p> </span><span style="font-family:Verdana;"></span><span style="font-family:;" "=""></span>展开更多
基金Project(21471162) supported by the National Natural Science Foundation of ChinaProject(2015H6016) supported by the Science and Technology Project of Fujian Province,China
文摘A new design route was presented to fabricate cobalt aluminum-layered double hydroxide(CoAl-LDH)thin layers whichgrow on carbon spheres(CSs)through a growth method.The CoAl-LDH thin layers consist of nanoflakes with a thickness of20nm.The galvanostatic charge-discharge test of the CoAl-LDH/CSs composite shows a great specific capacitance of1198F/g at1A/g(based on the mass of the CoAl-LDH/CSs composite)in6mol/L KOH solution,and the composite displays an impressive specificcapacitance of920F/g even at a high current density of10A/g.Moreover,the composite remains a specific capacitance of928F/gafter1000cycles at2A/g,and the specific capacitance retention is84%,indicating that the composite has high specific capacitance,excellent rate capability and good cycling stability in comparison to pristine CoAl-LDH.
基金supports for this work from National Key R&D Program of China(No.2022YFC2906300)the National Natural Science Foundation of China(No.52204283)+2 种基金the Natural Science Foundation of Hubei Province of China(No.2021CFB554)the Key Project of the Science and Technology Research of Hubei Provincial Department of Education(No.D20221605)the CONACYT through the project A1-S-8817.L.J.Z.would like to thank CONACYT for the scholarship for granting his the scholarship No.847199 during his Ph.D study.
文摘Lithium-aluminum layered double hydroxides(LiAl-LDH)have been be successfully applied in commercial-scale for lithium extraction from salt lake brine,however,further advancement of their applications is hampered by suboptimal Li^(+)adsorption performance and ambiguous extraction process.Herein,a doping engineering strategy was developed to fabricate novel Zn^(2+)-doped LiAl-LDH(LiZnAl-LDH)with remarkable higher Li^(+)adsorption capacity(13.4 mg/g)and selectivity(separation factors of 213,834,171 for Li^(+)/K^(+),Li^(+)/Na^(+),Li^(+)/Mg^(2+),respectively),as well as lossless reusability in Luobupo brine compared to the pristine LiAl-LDH.Further,combining experiments and simulation calculations,it was revealed that the specific surface area,hydrophilic,and surface attraction for Li^(+)of LiZnAl-LDH were significantly improved,reducing the adsorption energy(Ead)and Gibbs free energy(ΔG),thus facilitating the transfer of Li^(+)from brine into interface followed by insertion into voids.Importantly,the intrinsic oxygen vacancies derived from Zn-doping depressed the diffusion energy barrier of Li^(+),which accelerated the diffusion process of Li^(+)in the internal bulk of LiZnAl-LDH.This work provides a general strategy to overcome the existing limitations of Li^(+)recovery and deepens the understanding of Li^(+)extraction on LiAl-LDH.
基金the financial supports from the National Natural Science Foundation of China(Nos.51704011,51904003)the Joint Funds of the National Natural Science Foundation of China(No.U1703130)。
基金supported by the National Key Research and Development Program (No.2016YFA0202500)CAS Key Laboratory of Carbon Materials (No.KLCMKFJJ1701)
文摘With the growing concerns on global energy crisis and the greenhouse effect,the exploration on renewable energy and related emerging energy conversion and storage technologies are highly interested [1].Lithium sulfur (Li–S) battery system receives great attention for its high theoretical specific energy(2600 Wh/kg),which is deemed to be a promising candidate as next generation high energy density batteries [2].
文摘<span style="font-family:Verdana;"> <span style="font-family:;" "="">LDH-phases become increasingly interesting due to their broad ability to be able to incorporate many different cat</span><span style="font-family:;" "="">ions</span><span style="font-family:;" "=""> and anions. The intercalation of methanesulfonate and ethanesulfonate into a Li-LDH as well as the behavior of the interlayer structure as a function of the temperature is presented. A hexagonal P6<sub>3</sub>/m [LiAl<sub>2</sub>(OH)<sub>6</sub>][Cl?1</span><span style="font-family:;" "="">.</span><span style="font-family:;" "="">5H<sub>2</sub>O] (Li-Al-Cl) precursor LDH was synthesized by hydrothermal treating of a LiCl solution with <i>γ</i>-Al(OH)<sub>3</sub>. This precursor was used to intercalate methanesulfonate (CH<sub>3</sub>O<sub>3</sub>S<sup>?</sup>) and ethanesulfonate (C<sub>2</sub>H<sub>5</sub>O<sub>3</sub>S<sup>?</sup>) through anion exchange by stirring Li-Al-Cl in a solution of the respective organic Li-salt (90?C, 12 h). X-ray diffraction pattern showed an increase of the interlayer space <i>c</i></span><i><span style="font-family:;" "="">'</span></i><span style="font-family:;" "=""> (d<sub>001</sub>) of Li-Al-methanesulfonate (Li-Al-MS) with 1.2886 nm and Li-Al-ethanesulfonate (Li-Al-ES) with 1.3816 nm compared to the precursor with 0.7630 nm. Further investigations with Fourier-transform infrared spectroscopy and scanning electron microscopy confirmed a complete anion exchange of the organic molecules with the precursor Cl<sup>?</sup>. Both synthesized LDH compounds [LiAl<sub>2</sub>(OH)<sub>6</sub>]CH<sub>3</sub>SO<sub>3</sub>?nH<sub>2</sub>O (n = 2.24</span><span style="font-family:;" "="">-</span><span style="font-family:;" "="">3.72 (Li-Al-MS) and [LiAl<sub>2</sub>(OH)<sub>6</sub>]C<sub>2</sub>H<sub>5</sub>SO<sub>3</sub>}?nH<sub>2</sub>O (n = 1.5) (Li-Al-ES) showed a monomolecular interlayer structure with additional interlayer water at room temperature. By increasing the temperature, the interlayer water was removed and the interlayer space <i>c</i></span><i><span style="font-family:;" "="">'</span></i><span style="font-family:;" "=""> of Li-Al-MS decreased to 0.87735 nm (at 55?C). Calculations showed that a slight displacement of the organic molecules is necessary to achieve this interlayer space. Different behavior of Li-Al-ES could be observed during thermal treatment. Two phases coexisted at 75?C </span><span style="font-family:;" "="">-</span><span style="font-family:;" "=""> 85?C, one with a reduced <i>c</i></span><i><span style="font-family:;" "="">'</span></i><span style="font-family:;" "=""> (0.9015 nm, 75?C) and one with increased <i>c</i></span><i><span style="font-family:;" "="">'</span></i><span style="font-family:;" "=""> (1.5643 nm, 85?C) compared to the LDH compound at room temperature. The increase of <i>c</i></span><i><span style="font-family:;" "="">'</span></i><span style="font-family:;" "=""> is due to the formation of a bimolecular interlayer structure.</span><span style="font-family:;" "=""></span> <p> <br /> </p> </span><span style="font-family:Verdana;"></span><span style="font-family:;" "=""></span>
文摘为有效提升锂氧电池的电化学性能,以钴铝复合金属氢氧化物(Co Al-LDH)作为催化剂,研究其对锂空气电池性能的影响.采用工艺简单、成本低廉的共沉淀法将其与石墨烯复合后,制备出r GO/Co Al-LDH纳米复合材料,并将其应用于锂氧电池.采用X射线衍射、拉曼光谱、同步热分析和扫描电镜对材料结构进行表征,利用恒流充放电测试、交流阻抗测试(EIS)和线性伏安扫描(LSV)对电池电化学性能进行表征.研究结果表明:制备得到的纳米复合材料可明显提升氧还原反应(ORR)的催化活性,首次放电容量达到2 662 m A·h·g^(-1),与单纯石墨烯相比提高了51.5%,同时充电电位降低了430 m V.循环过程中电池库伦效率较高,电池循环性能得到显著改善.