Dual Layer Coating Strategy Utilizing N-doped Carbon and Reduced Graphene Oxide for High-Performance LiFePO4 Cathode Material

作者：Oh Jiseop; Lee Jeongyeon; Hwang Taejin; Kim Jong Min; Seoung Kwang dong; Piao Yuanzhe^*

来源：Electrochimica Acta, 2017, 231: 85-93.

DOI：10.1016/j.electacta.2017.01.185

• LiFePO(4)nanoplates
• polydopamine
• reduced graphene oxide
• nitrogen-doped carbon
• rate performance

Lithium iron phosphate (LiFePO4, LFP) has two major drawbacks such as low lithium ion diffusivity and poor electric conductivity, which limit the wider application as a cathode material for lithium ion batteries. In this work, we report a dual carbon layer coating strategy for LFP, which uses polydopamine-derived nitrogen-doped carbon (N-doped carbon) and reduced graphene oxide (RGO). These dual carbon layers are prepared by a one-pot polymerization process and thermal treatment. The dual carbon coated LFP has a rate capability with a discharge capacity of 98 mAh/g at 30C, cycling performance with a discharge capacity of 115 mAh/g at 10C, and 96.18% capacity retention after 700 cycles. The high rate performance and the excellent long-term cycling stability can be attributed to the enhanced electric conductivity with N-doped carbon coating, the well-connected electron pathway, and the fast Li+ ion diffusion induced by the small size of the particles. Consequently, coating of LFP with polydopamine derived N-doped carbon and RGO produces a material suitable for high-performance lithium-ion batteries.

• 出版日期2017-3-20