tailieunhanh - Báo cáo hóa học: " Synthesis and characterization of integrated layered nanocomposites for lithium ion batteries"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Synthesis and characterization of integrated layered nanocomposites for lithium ion batteries | Gim et al. Nanoscale Research Letters 2012 7 60 http content 7 1 60 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Synthesis and characterization of integrated layered nanocomposites for lithium ion batteries Jihyeon Gim Jinju Song Hyosun Park Jungwon Kang Kangkun Kim Vinod Mathew and Jaekook Kim Abstract The series of Li NixMxLi1 3-xMn2 3-x O2 cathodes where M is cobalt or chromium with a wide compositional range x from 0 to were prepared by hydroxide coprecipitation method with subsequent quenching. The sample structures were investigated using X-ray diffraction results which were indexed completely on the basis of a trigonal structure of space group R3m with monoclinic C2 m phase as expected. The morphologies and electrochemical properties of the samples obtained were compared as the value of x and substituted transition metal. The particle sizes of cobalt-substituted Li NixCoxLi1 3-xMn2 3-x O2 samples are much smaller than those of the Li NixCrxLi1 3-xMn2 3-x O2 system. The electrode containing Li NixCoxLi1 3-xMn2 3-x O2 with x delivered a discharge capacity of above 200 mAh g after 10 cycles due to the activation of Li2MnO3. PACS . Keywords lithium ion batteries cathodes nanocomposites coprecipitation Introduction The development of rechargeable lithium ion batteries depends critically on the technological advances in electrode materials. Over the years several compounds such as spinel LiMn2O4 olivine LiFePO4 1 and layered LiCoO2 and LiNiO2 have been studied extensively by many researchers as cathode materials for lithium ion batteries. In fact LiMn2O4 and LiFePO4 have distinct advantages of being cost-effective and environmentally benign. However LiMn2O4 suffers from capacity fading due to the dissolution of manganese and Jahn-Teller distortion 2 3 while LiFePO4 delivers insufficient capacity and low electronic conductivity 4 . Commercially used LiCoO2 cathode has .