Conformal Coating Strategy Comprising N-doped Carbon and Conventional Graphene for Achieving Ultrahigh Power and Cyclability of LiFePO4
| Autor: | Jeong Taik Lee, Kan Zhang, Jong Hyeok Park, Jung Hyun Kim, Ping Li, Gi-Ra Yi, Byoungwoo Kang |
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| Rok vydání: | 2015 |
| Předmět: |
Materials science
Graphene Mechanical Engineering Lithium iron phosphate Diffusion Conformal coating Bioengineering Nanotechnology General Chemistry engineering.material Condensed Matter Physics law.invention chemistry.chemical_compound chemistry Coating Chemical engineering Electrical resistivity and conductivity law Electrode engineering General Materials Science Nanorod |
| Zdroj: | Nano Letters. 15:6756-6763 |
| ISSN: | 1530-6992 1530-6984 |
| Popis: | Surface carbon coating to improve the inherent poor electrical conductivity of lithium iron phosphate (LiFePO4, LFP) has been considered as most efficient strategy. Here, we also report one of the conventional methods for LFP but exhibiting a specific capacity beyond the theoretical value, ultrahigh rate performance, and excellent long-term cyclability: the specific capacity is 171.9 mAh/g (70 μm-thick electrode with ∼10 mg/cm(2) loading mass) at 0.1 C (17 mA/g) and retains 143.7 mAh/g at 10 C (1.7 A/g) and 95.8% of initial capacity at 10 C after 1000 cycles. It was found that the interior conformal N-C coating enhances the intrinsic conductivity of LFP nanorods (LFP NR) and the exterior reduced graphene oxide coating acts as an electrically conducting secondary network to electrically connect the entire electrode. The great electron transport mutually promoted with shorten Li diffusion length on (010) facet exposed LFP NR represents the highest specific capacity value recorded to date at 10 C and ultralong-term cyclability. This conformal carbon coating approach can be a promising strategy for the commercialization of LFP cathode in lithium ion batteries. |
| Databáze: | OpenAIRE |
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