New catalysts combined with an organic or inorganic lithium salt (lithium acetate or lithiumchloride) and a conventional catalyst for the transesterification of dimethyl terephthalate withethylene glycol have been stu...New catalysts combined with an organic or inorganic lithium salt (lithium acetate or lithiumchloride) and a conventional catalyst for the transesterification of dimethyl terephthalate withethylene glycol have been studied. Reaction mechanism in presence of lithium-base catalyst hasbeen proposed. A synergistic action of two classes of catalysts creates the speed-up of initial re-action particularly in presence of lithium acetate. The presence of lithium base catalyst can re-duce diethylene glycol content and raise the melting point of final PET product, but almostuneffect PET molecular weight distribution.展开更多
本文以醋酸盐为原料,采用溶胶凝胶法制备富锂锰基固溶体正极材料Li_(1.2)Ni_(0.2)Mn_(0.6)O_2。研究Co掺杂后对Li1.2Ni0.2-x/2Mn0.6-x/2CoxO2(x=0,0.01,0.02,0.05)材料结构以及电化学性能的影响。XRD和SEM测试表明:Co掺杂后样品结构未...本文以醋酸盐为原料,采用溶胶凝胶法制备富锂锰基固溶体正极材料Li_(1.2)Ni_(0.2)Mn_(0.6)O_2。研究Co掺杂后对Li1.2Ni0.2-x/2Mn0.6-x/2CoxO2(x=0,0.01,0.02,0.05)材料结构以及电化学性能的影响。XRD和SEM测试表明:Co掺杂后样品结构未发生改变,均属于富锂锰基正极材料。电化学测试表明:Co掺杂能改善材料的倍率性能,提高材料的放电比容量。其中,x=0.02的材料Li1.2Ni0.19Mn0.59Co0.02O2具有最优异的电化学性能,0.05 C下的首次放电比容量由未掺杂的的217 m Ah·g-1提升至332.6 m Ah·g-1;0.1 C下经40次循环后放电比容量为171.6 m Ah·g-1,保持率为85.5%。展开更多
文摘New catalysts combined with an organic or inorganic lithium salt (lithium acetate or lithiumchloride) and a conventional catalyst for the transesterification of dimethyl terephthalate withethylene glycol have been studied. Reaction mechanism in presence of lithium-base catalyst hasbeen proposed. A synergistic action of two classes of catalysts creates the speed-up of initial re-action particularly in presence of lithium acetate. The presence of lithium base catalyst can re-duce diethylene glycol content and raise the melting point of final PET product, but almostuneffect PET molecular weight distribution.
文摘本文以醋酸盐为原料,采用溶胶凝胶法制备富锂锰基固溶体正极材料Li_(1.2)Ni_(0.2)Mn_(0.6)O_2。研究Co掺杂后对Li1.2Ni0.2-x/2Mn0.6-x/2CoxO2(x=0,0.01,0.02,0.05)材料结构以及电化学性能的影响。XRD和SEM测试表明:Co掺杂后样品结构未发生改变,均属于富锂锰基正极材料。电化学测试表明:Co掺杂能改善材料的倍率性能,提高材料的放电比容量。其中,x=0.02的材料Li1.2Ni0.19Mn0.59Co0.02O2具有最优异的电化学性能,0.05 C下的首次放电比容量由未掺杂的的217 m Ah·g-1提升至332.6 m Ah·g-1;0.1 C下经40次循环后放电比容量为171.6 m Ah·g-1,保持率为85.5%。
