The alumina solubility in the title system within the composition range of KR{m（K3AlF6）/[m（K3AlF6）＋ m（Na3AlF6）]} 10%―50%, a ternary Na3AlF6-K3AlF6-AlF3 molten system with 23%―29%（mass fraction） AlF3 was inv...The alumina solubility in the title system within the composition range of KR{m（K3AlF6）/[m（K3AlF6）＋ m（Na3AlF6）]} 10%―50%, a ternary Na3AlF6-K3AlF6-AlF3 molten system with 23%―29%（mass fraction） AlF3 was investigated by measuring the mass loss of a rotating sintered corundum disc. And the following empirical equation was derived when superheat degree was no more than 60 °C： w（Al2O3）sat=A×（T/1000）B, where A= –1.85774＋ 26.754234w（AlF3）–0.3683–0.00783KR2.363＋0.010266KR2.3048＋0.7902w（AlF3）0.00652, B=112.4625–53.2567w（AlF3）0.4236＋ 5.1079w（AlF3）0.9241＋0.01542w（AlF3）1.3540. Considering both higher alumina solubility and not too high superheat de gree are required, alumina solubility of different compositions at not the same temperature but the same superheat degree was studied, which will be more industrial helpful for selecting prospective compositions. The results show that the composition deserved to be further tested in lower temperature cells is 10%―30% KR and 23%―26%（mass fraction） AlF3.展开更多
Layered solid solution material Lil.2Nio.2Mn0.602 is synthesized and the A1F3 is added to improve the electrochemical performance. X-ray diffraction （XRD） results show that the Lil.2Nio.2Mno.602 samples exhibit laye...Layered solid solution material Lil.2Nio.2Mn0.602 is synthesized and the A1F3 is added to improve the electrochemical performance. X-ray diffraction （XRD） results show that the Lil.2Nio.2Mno.602 samples exhibit layered characteristics. The A1F3 additive is detected by transmission electron microscope （TEM） technology. The electrochemical tests show that Lil.2Nio.2Mno.602 electrode with A1F3 added delivers better discharge capacity （240mA.h/g）, first coulomb efficiency 79.2%, cyclic performance （capacity retention ratio of 100.6% after 50 cycles）, and rate capacity （68 mA. h/g at 10 capacity （C）） than the pristine sample. Electrochemical impedance spectroscopy （EIS） results show that the charge transfer resistance of Lil.2Ni0.2Mno.602 electrode with A1F3 added increases slower than that of pristine Lil.2Ni0.2Mno.602 after cycling, which is responsible for better cyclic and rate performance.展开更多
文摘以天然石墨为原料,通过机械高速分散设备将天然石墨和Al F3在液相介质中充分混合,混合液喷雾干燥后获得颗粒形态均匀分散的Al F3包覆天然石墨(NG)复合负极材料(AF/NG)。一方面Al F3包覆层有助于在天然石墨表面形成稳定的SEI膜,提升材料的循环稳定性;另一方面Al F3的引入改善了锂离子在天然石墨内外的迁移与扩散,提升复合材料的倍率性能,0.5C倍率下放电比容量达到278 m Ah·g-1,同等倍率下比未包覆Al F3样品提高了78 m Ah·g-1。合成工艺简单易管控,适合规模化商业生产。
基金Supported by the National Basic Research Program of China(No.2005CB623703)the National High-Tech Research and Development Program of China(No.2008AA030503)
文摘The alumina solubility in the title system within the composition range of KR{m（K3AlF6）/[m（K3AlF6）＋ m（Na3AlF6）]} 10%―50%, a ternary Na3AlF6-K3AlF6-AlF3 molten system with 23%―29%（mass fraction） AlF3 was investigated by measuring the mass loss of a rotating sintered corundum disc. And the following empirical equation was derived when superheat degree was no more than 60 °C： w（Al2O3）sat=A×（T/1000）B, where A= –1.85774＋ 26.754234w（AlF3）–0.3683–0.00783KR2.363＋0.010266KR2.3048＋0.7902w（AlF3）0.00652, B=112.4625–53.2567w（AlF3）0.4236＋ 5.1079w（AlF3）0.9241＋0.01542w（AlF3）1.3540. Considering both higher alumina solubility and not too high superheat de gree are required, alumina solubility of different compositions at not the same temperature but the same superheat degree was studied, which will be more industrial helpful for selecting prospective compositions. The results show that the composition deserved to be further tested in lower temperature cells is 10%―30% KR and 23%―26%（mass fraction） AlF3.
基金the Postdoctoral Foundation of China (No.2012M511211)the Postdoctoral Foundation of Jiangsu Province(No.1102121C)
文摘Layered solid solution material Lil.2Nio.2Mn0.602 is synthesized and the A1F3 is added to improve the electrochemical performance. X-ray diffraction （XRD） results show that the Lil.2Nio.2Mno.602 samples exhibit layered characteristics. The A1F3 additive is detected by transmission electron microscope （TEM） technology. The electrochemical tests show that Lil.2Nio.2Mno.602 electrode with A1F3 added delivers better discharge capacity （240mA.h/g）, first coulomb efficiency 79.2%, cyclic performance （capacity retention ratio of 100.6% after 50 cycles）, and rate capacity （68 mA. h/g at 10 capacity （C）） than the pristine sample. Electrochemical impedance spectroscopy （EIS） results show that the charge transfer resistance of Lil.2Ni0.2Mno.602 electrode with A1F3 added increases slower than that of pristine Lil.2Ni0.2Mno.602 after cycling, which is responsible for better cyclic and rate performance.
