Details

Autor(en) / Beteiligte

• Gao, Chao
• Zhou, Jian
• Liu, Guizhen
• Wang, Lin

Titel

Microwave-assisted synthesis and surface decoration of LiFePO4 hexagonal nanoplates for lithium-ion batteries with excellent electrochemical performance

Ist Teil von

• Journal of materials science, 2017-02, Vol.52 (3), p.1590-1602

Ort / Verlag

New York: Springer US

Erscheinungsjahr

2017

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Microwave-assisted synthesis of electrode materials for lithium-ion batteries has drawn extensive attention owing to the unique microwave dielectric heating. In this work, olivine LiFePO 4 hexagonal nanoplates, with a short b -axis, were successfully synthesized using a single-mode microwave-assisted hydrothermal system at 160 °C just in 20 min. Microwave irradiation can lower the synthesis temperature and shorten the synthesis time dramatically. The growth process of LiFePO 4 hexagonal nanoplates with microwave irradiation time was investigated. The role of electromagnetic field in the formation and the quality of the resulting LiFePO 4 were explored. In order to enhance the electrochemical properties of LiFePO 4 hexagonal nanoplates, LiFePO 4 /C and LiFePO 4 /rGO have been obtained through surface decoration of LiFePO 4 nanoplates by ex situ carbon coating and in situ reduced graphene oxide (rGO) coating. The electrochemical analysis demonstrated that LiFePO 4 /rGO had more excellent electrochemical performance; the initial discharge capacity at 0.1 C was up to 167.2 mAh g −1 which was very close to the theoretical value (170 mAh g −1 ). This is because the in situ coating can achieve a complete coating of the surface and rGO has a higher electrical conductivity. The rGO layer can boost the transport speed of the lithium ions and electrons, and reduce the charge transfer resistance of Li ion insertion/extraction. Furthermore, the unique structure of the nanoplates with a short b -axis is favored to shorten the migration of Li + ion.