Wang Zhongyu, Lu Yangcheng
State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
ACS Omega. 2019 Sep 9;4(12):14790-14799. doi: 10.1021/acsomega.9b01343. eCollection 2019 Sep 17.
In this article, nanostructured amorphous FePO (a-FePO)-carbon nanotube (CNT) composites, with high purity of FePO and a controllable FePO/C ratio, were directly synthesized by a fast nanoprecipitation process in a microreactor, using Fe(NO) and (NH)PO as precursors. Oxidized CNTs are well dispersed via strong electrostatic repulsion in a high pH solution system. Subsequently, a-FePO nanoparticles are adhered onto CNTs just following the fast nanoprecipitation process; then, the precipitated composites are compacted by ball-milling, forming a compact conductive network with well dispersed and highly loaded active materials. As cathode materials for lithium-ion batteries, the composites exhibit a capacity of 175.8 mAh g at 0.1 C, close to the theoretical capacity (178 mAh g), and a good cycle performance with a reversible capacity of 137.0 mAh g after 500 cycles at 5 C. Importantly, the enhanced micromixing enables fast nanoprecipitation in suspension and opens a shortcut for constructing nanostructured composites that have potential in functionalization and are easy to handle.
在本文中，以Fe(NO)和(NH)PO为前驱体，通过微反应器中的快速纳米沉淀法直接合成了具有高纯度FePO和可控FePO/C比的纳米结构非晶态FePO（a-FePO）-碳纳米管（CNT）复合材料。氧化的碳纳米管通过在高pH值溶液体系中的强静电排斥作用而得到良好分散。随后，在快速纳米沉淀过程之后，a-FePO纳米颗粒附着在碳纳米管上；然后，通过球磨将沉淀的复合材料压实，形成具有良好分散且高负载活性材料的致密导电网络。作为锂离子电池的正极材料，该复合材料在0.1 C时的容量为175.8 mAh g，接近理论容量（178 mAh g），并且在5 C下循环500次后具有137.0 mAh g的可逆容量，循环性能良好。重要的是，增强的微混合能够在悬浮液中实现快速纳米沉淀，并为构建在功能化方面具有潜力且易于处理的纳米结构复合材料开辟了一条捷径。
