A three-dimensional interlayer composed of graphene and porous carbon for Long-life, High capacity Lithium-Iron Fluoride Battery

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• 作者：Juan Yang ; Zhanglin Xu ; Hongxu Sun ; Xiangyang Zhou ; ^{hncsyjy308@163.com" class="auth_mail" title="E-mail the corresponding author}
• 关键词：iron fluoride ; interlayer ; porous carbon ; graphene sheets
• 刊名：Electrochimica Acta
• 出版年：2016
• 出版时间：1 December 2016
• 年：2016
• 卷：220
• 期：Complete
• 页码：75-82
• 全文大小：2725 K

文摘

We design a macroscopic structure composing of porous carbon and graphene sheets, which are coated onto a cellulose paper as an interlayer inserted between electrode and separator. The interlayer mainly acts as a divertor to accommodate the discharge products breaking away from the electrode by mechanical degradation or cathode dissolution during cycling and keeps the close contact with current collector.

Iron fluoride is a new-type lithium storage material developed in recent years, which can act as a cathode material candidate for the rechargeable lithium ion battery due to their large theoretical capacity and relatively high operating potential. Specifically, FeF₃·0.33H₂O, which possesses unusual tunnel structure, is attracting more and more attentions. However, FeF₃·0.33H₂O suffers from the poor electronic conductivity and volume effect during cycling, causing the large capacity fading. In this study, we design a macroscopic structure composing of porous carbon and graphene sheets, which are coated onto a cellulose paper as an interlayer inserted between electrode and separator. The interlayer can not only enhance the electronic conductivity, but also absorb the FeF₃·0.33H₂O nanoparticles breaking away from the Al foil due to the volume effect upon cycling. When the interlayer is applied in battery, discharge capacities of 600 and 460 mAh g⁻¹ can be achieved at the rates of 100 and 600 mA g⁻¹ after 60 cycles, respectively. Furthermore, the capacity of 435 mAh g⁻¹ can be still retained at a high rate of 1000 mA g⁻¹ after 250 cycles. The results demonstrate a potential feasibility for the porous carbon/graphene sheets to be applied to obtain a high-performance lithium-iron fluoride battery.