Desired crystal oriented LiFePO4 nanoplatelets in situ anchored on a graphene cross-linked conductive network for fast lithium storage

作者：Wang, Bo; Liu, Anmin; Al Abdulla, Wael; Wang, Dianlong^*; Zhao, X. S.

来源：Nanoscale, 2015, 7(19): 8819-8828.

DOI：10.1039/c5nr01831e

• SUPERIOR CATHODE MATERIAL
• LI-ION BATTERIES
• ELECTROCHEMICAL PERFORMANCE
• LIFEPO4/GRAPHENE COMPOSITES
• 3-DIMENSIONAL GRAPHENE
• CARBON
• NANOPARTICLES
• NANOCOMPOSITES
• NANOCRYSTALS
• ORIENTATION

Electron transfer and lithium ion diffusion rates are the key factors limiting the lithium ion storage in anisotropic LiFePO4 electrodes. In this work, we employed a facile solvothermal method to synthesize a "platelet-on-sheet" LiFePO4/graphene composite (LFP@GNs), which is LiFePO4 nanoplatelets in situ grown on graphene sheets with highly oriented (010) facets of LiFePO4 crystals. Such a two-phase contact mode with graphene sheets cross-linked to form a three-dimensional porous network is favourable for both fast lithium ion and electron transports. As a result, the designed LFP@GNs displayed a high rate capability (similar to 56 mA h g(-1) at 60 C) and long life cycling stability (similar to 87% capacity retention over 1000 cycles at 10 C). For comparison purposes, samples ex situ modified with graphene (LFP/GNs) as well as pure LiFePO4 platelets (LFP) were also prepared and investigated. More importantly, the obtained LFP@GNs can be used as a basic unit for constructing more complex structures to further improve electrochemical performance, such as coating the exposed LFP surface with a thin layer of carbon to build a C@LFP@GN composite to further enhance its cycling stability (similar to 98% capacity retention over 1000 cycles at 10 C).

• 出版日期2015
• 单位哈尔滨工业大学; 青岛大学