화학공학소재연구정보센터
Journal of Colloid and Interface Science, Vol.493, 241-248, 2017
A three-dimensional core-shell nanostructured composite of polypyrrole wrapped MnOL2/reduced graphene oxide/carbon nanotube for high performance lithium ion batteries
Manganese oxides are promising anode materials for their high-energy density. However, they suffer from poor rate capability and fast capacity fading. Herein, we construct a three-dimensional (3D) core shell structured polypyrrole (PPy)/MnO2-reduced graphene oxide (rGO)-carbon nanotubes (CNTs) composite via a facile two-step method. In the structure, the CNTs can facilitate fast electron conduction and keep structural integrity. The flexible and conductive rGO nanosheets work as both a reactive material and a carrier for MnO2 in-situ growth. The MnO2 nanosheets well distributed on the rGO/CNTs scaffold favor the energy storage by way of fast Li insertion and extraction. PPy nanoparticles (similar to 10 nm) well wrapped on the MnO2 nanosheets not only enable the interfacial stabilization, but also provide a buffer layer to accommodate the volume expansion. As a result, the as-prepared PPy/Mn02-rGO-CNTs composite exhibits high specific capacity, excellent cycling stability and good rate capability. A reversible specific capacity of 1748.1 mA h g(-1) is achieved at the current density of 100 mA g(-1) after 200 cycles. Even at a high current density of 1000 mA g(-1), the composite still exhibits 941.1 mA h g(-1) after 1200 cycles. The design strategy of the composite can be extended to other high-capacity metal oxide material. (C) 2017 Elsevier Inc. All rights reserved.