Effect of lithium ion in sodium aluminate solution on precipitation rate,lithium content,morphology,and crystallization of alumina trihydrate(ATH) was investigated. Results showed that increasing lithium ion concentra...Effect of lithium ion in sodium aluminate solution on precipitation rate,lithium content,morphology,and crystallization of alumina trihydrate(ATH) was investigated. Results showed that increasing lithium ion concentration in solution improved the precipitation rate and lithium content in ATH,whereas reduced the mass fraction of lithium precipitation from solution. Lithium ion in solution generated the fine ATH, and thereafter significantly increased the total particle number due to the preferential nucleation.Elevating temperature or reducing lithium ion concentration decreased lithium content in ATH and reduced the fine particle amount.Moreover, lithium ion in the solution changed the morphology of ATH by improving the growth of the(110) and(200) planes of gibbsite.A large amount of fine bar-or flake-shaped ATH attached on the coarse particles also benefited the secondary nucleation and led to the poor strength of alumina.All results will further contribute to improving the quality of alumina.展开更多
Here we demonstrate a theory-driven, novel dual-shell coating system of Li_(2)SrSiO_(4) and Al_(2)O_(3), achieved via a facile and scalable sol-gel technique on LiCoO_(2) electrode particles. The optimal thickness of ...Here we demonstrate a theory-driven, novel dual-shell coating system of Li_(2)SrSiO_(4) and Al_(2)O_(3), achieved via a facile and scalable sol-gel technique on LiCoO_(2) electrode particles. The optimal thickness of each coating can lead to increased specific capacity(~185 m Ah/g at 0.5 C-rate) at a cut-off potential of 4.5 V, and greater cycling stability at very high C rates(up to 10 C) in half-cells with lithium metal. The mechanism of this superior performance was investigated using a combination of X-ray and electron characterization methods. It shows that the results of this investigation can inform future studies to identify still better dual-shell coating schemes, achieved by such industrially feasible techniques, for application on similar, nickel-rich cathode materials.展开更多
Li（Mn1/3Ni1/3Co1/3）O2 cathode materials were fabricated by a hydroxide precursor method. A1203 was coated on the surface of the Li（Mn1/3Ni1/3Co1/3）O2 through a simple and effective one-step electrostatic self-asse...Li（Mn1/3Ni1/3Co1/3）O2 cathode materials were fabricated by a hydroxide precursor method. A1203 was coated on the surface of the Li（Mn1/3Ni1/3Co1/3）O2 through a simple and effective one-step electrostatic self-assembly method. In the coating process, a NaHCO3- H2CO3 buffer was formed spontaneously when CO2 was introduced into the NaAlO2 solution. Compared with bare Li（Mn1/3Ni1/3Co1/3）O2, the surface-modified samples exhibited better cycling performance, rate capability and rate capability retention. The Al2O3-coated Li（Mn1/3Ni1/3Co1/3）O2 electrodes delivered a discharge capacity of about 115 mAh.g-1 at 2 A.g-1, but only 84 mAh.g-1 for the bare one. The capacity retention of the Al2O3-coated Li（Mn1/3Ni1/3Co1/3）O2 was 90.7% after 50 cycles, about 30% higher than that of the pristine one.展开更多
基金Project(2015BAB04B01)supported by the National Key Technology Research&Development Program of ChinaProject(CSUZC201811)supported by the Open-End Fund for the Valuable and Precision Instruments of Central South University,China
文摘Effect of lithium ion in sodium aluminate solution on precipitation rate,lithium content,morphology,and crystallization of alumina trihydrate(ATH) was investigated. Results showed that increasing lithium ion concentration in solution improved the precipitation rate and lithium content in ATH,whereas reduced the mass fraction of lithium precipitation from solution. Lithium ion in solution generated the fine ATH, and thereafter significantly increased the total particle number due to the preferential nucleation.Elevating temperature or reducing lithium ion concentration decreased lithium content in ATH and reduced the fine particle amount.Moreover, lithium ion in the solution changed the morphology of ATH by improving the growth of the(110) and(200) planes of gibbsite.A large amount of fine bar-or flake-shaped ATH attached on the coarse particles also benefited the secondary nucleation and led to the poor strength of alumina.All results will further contribute to improving the quality of alumina.
基金supported by the U.S. National Science Foundation (CBET-1949870, CBET-2016192, and DMR-1832803)Part of the research was conducted at the Northwest Nanotechnology Infrastructure, a National Nanotechnology Coordinated Infrastructure (NNCI) site at Oregon State University, which is supported, in part, by the U.S. National Science Foundation (NNCI-1542101 and NCC-2025489), and Oregon State University。
文摘Here we demonstrate a theory-driven, novel dual-shell coating system of Li_(2)SrSiO_(4) and Al_(2)O_(3), achieved via a facile and scalable sol-gel technique on LiCoO_(2) electrode particles. The optimal thickness of each coating can lead to increased specific capacity(~185 m Ah/g at 0.5 C-rate) at a cut-off potential of 4.5 V, and greater cycling stability at very high C rates(up to 10 C) in half-cells with lithium metal. The mechanism of this superior performance was investigated using a combination of X-ray and electron characterization methods. It shows that the results of this investigation can inform future studies to identify still better dual-shell coating schemes, achieved by such industrially feasible techniques, for application on similar, nickel-rich cathode materials.
基金supported by the National Natural Science Foundation of China(21273222)
文摘Li（Mn1/3Ni1/3Co1/3）O2 cathode materials were fabricated by a hydroxide precursor method. A1203 was coated on the surface of the Li（Mn1/3Ni1/3Co1/3）O2 through a simple and effective one-step electrostatic self-assembly method. In the coating process, a NaHCO3- H2CO3 buffer was formed spontaneously when CO2 was introduced into the NaAlO2 solution. Compared with bare Li（Mn1/3Ni1/3Co1/3）O2, the surface-modified samples exhibited better cycling performance, rate capability and rate capability retention. The Al2O3-coated Li（Mn1/3Ni1/3Co1/3）O2 electrodes delivered a discharge capacity of about 115 mAh.g-1 at 2 A.g-1, but only 84 mAh.g-1 for the bare one. The capacity retention of the Al2O3-coated Li（Mn1/3Ni1/3Co1/3）O2 was 90.7% after 50 cycles, about 30% higher than that of the pristine one.
