Zhang Zhibo, Chen Zhihao, Mai Zhaoxu, Peng Kunyao, Deng Qinglin, Bayaguud Aruuhan, Zhao Pengfei, Fu Yanpeng, Yu Yan, Zhu Changbao
Department of Materials Science and Engineering, Sun-Yat Sen University, Guangzhou, 510275, Guangdong, P. R. China.
School of Materials and Energy, Guangdong University of Technology, Guangzhou, 510006, Guangdong, P. R. China.
Small. 2019 Apr;15(14):e1900356. doi: 10.1002/smll.201900356. Epub 2019 Feb 21.
Developing high power-high energy electrochemical energy storage systems is an ultimate goal in the energy storage field, which is even more difficult but significant for low-cost sodium ion batteries. Here, fluoride is successfully prepared by the electrostatic spray deposition (ESD) technique, which greatly expands the application scope of ESD. A two-step strategy (solvothermal plus ESD method) is proposed to construct a bicontinuous ordered network of 3D porous Na (VO) (PO ) F/reduced graphene oxide (NVOPF/rGO). This two-step strategy makes sure that NVOPF can be prepared by ESD, since it avoids the loss of F element during synthesis. The obtained NVOPF particles are as small as 15 nm, and the carbon content is only 3.5% in the final nanocomposite. Such a bicontinuous ordered network and small size of electroactive particles lead to the significant contribution of the pseudocapacitance effect to sodium storage, resulting in real high power-high energy sodium cathodes. The cathode exhibits excellent rate capability and cycling stability, whose rate performance is one of the best ever reported in both half cells and full cells. Moreover, this work provides a general and promising strategy for developing high power-high energy electrode materials for various electrochemical energy storage systems.
开发高功率-高能量的电化学储能系统是储能领域的最终目标，对于低成本钠离子电池而言，这一目标更具挑战性但意义重大。在此，通过静电喷雾沉积（ESD）技术成功制备了氟化物，这极大地拓展了ESD的应用范围。提出了一种两步策略（溶剂热法加ESD法）来构建三维多孔Na(VO)(PO)F/还原氧化石墨烯（NVOPF/rGO）的双连续有序网络。这种两步策略确保了NVOPF能够通过ESD制备，因为它避免了合成过程中F元素的损失。所获得的NVOPF颗粒小至15nm，最终的纳米复合材料中碳含量仅为3.5%。这种双连续有序网络和小尺寸的电活性颗粒导致赝电容效应在储钠过程中发挥显著作用，从而产生真正的高功率-高能量钠阴极。该阴极表现出优异的倍率性能和循环稳定性，其倍率性能在半电池和全电池中均是有史以来报道的最佳性能之一。此外，这项工作为开发用于各种电化学储能系统的高功率-高能量电极材料提供了一种通用且有前景的策略。
