Title of Paper:Interpenetrated Networks between Graphitic Carbon Infilling and Ultrafine TiO2 Nanocrystals with Patterned Macroporous Structure for High-Performance Lithium Ion Batteries

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Date of Publication:2017-06-21

Journal:ACS APPLIED MATERIALS & INTERFACES

Included Journals:SCIE、EI、PubMed、Scopus

Volume:9

Issue:24

Page Number:20491-20500

ISSN No.:1944-8244

Key Words:TiO2; macropore; mesopore; Li ion battery; carbon

Abstract:Interpenetrated networks between graphitic carbon infilling and ultrafine TiO2 nanocrystals with patterned macropores (100-200 nm) were successfully synthesized. Polypyrrole layer was conformably coated on the primary TiO2 nanoparticles (similar to 8 nm) by a photosensitive reaction and was then transformed into carbon infilling in the interparticle mesopores of the TiO2 nanoparticles. Compared to the carbon/graphene supported TiO2 nanoparticles or carbon coated TiO2 nanostructures, the carbon infilling would provide a conductive medium and buffer layer for volume expansion of the encapsulated TiO2 nanoparticles, thus enhancing conductivity and cycle stability of the C-TiO2 anode materials for lithium ion batteries (LIBs). In addition, the macropores with diameters of 100-200-nm in the C-TiO2 anode and the mesopores in carbon infilling could improve electrolyte transportation in the electrodes and shorten the lithium ion diffusion length. The C-TiO2 electrode can provide a large capacity of 192.8 mA h g(-1) after 100 cycles at 200 mA g(-1), which is higher than those of the pure macroporous TiO2 electrode (144.8 mA h g(-1)), C-TiO2 composite electrode without macroporous structure (128 mA h g(-1)) and most of the TiO2 based electrodes in the literature. Importantly, the C-TiO2 electrode exhibits a high rate performance and still delivers a high capacity of similar to 440 mA h g(-1) after 1000 cycles at 1000 mA g(-1) (similar to 5.88 C), suggesting good lithium storage properties of the macroporous C-TiO2 composites with high capacity, cycle stability, and rate capability. This work would be instructive for designing hierarchical porous TiO2 based anodes for high-performance LIBs.