Shi Chenglong, Xu Junling, Tao Tao, Lu Xiaoyi, Liu Guoping, Xie Fuqiang, Wu Sheng, Wu Yanxue, Sun Zhipeng
School of Materials and Energy, Guangdong University of Technology, Guangzhou, Guangdong, 510006, China.
Analysis and Test Center, Guangdong University of Technology, Guangzhou, Guangdong, 510006, China.
Small Methods. 2024 Mar;8(3):e2301277. doi: 10.1002/smtd.202301277. Epub 2023 Nov 27.
Sodium-ion batteries (SIBs) are widely considered a hopeful alternative to lithium-ion battery technology. However, they still face challenges, such as low rate capability, unsatisfactory cycling stability, and inferior variable-temperature performance. In this study, a hierarchical Na V (PO ) F (NVPF) @reduced graphene oxide (rGO)/carbon nanotube (CNT) composite (NVPF@rGO/CNT) is successfully constructed. This composite features 0D Na V (PO ) F nanoparticles are coated by a cross-linked 3D conductive network composed of 2D rGO and 1D CNT. Furthermore, the intrinsic Na storage mechanism of NVPF@rGO/CNT through comprehensive characterizations is unveiled. The synthesized NVPF@rGO/CNT exhibits fast ionic/electronic transport and excellent structural stability within wide working temperatures (-40-50 °C), owing to the zero-strain NVPF and the coated rGO/CNT conductive network that reduces diffusion distance for ions and electrons. Moreover, the stable integration between NVPF and rGO/CNT enables outstanding structural stability to alleviate strain and stress induced during the cycle. Additionally, a practice full cell is assembled employing a hard carbon anode paired with an NVPF@rGO/CNT cathode, which provides a decent capacity of 105.2 mAh g at 0.2 C, thereby attaining an ideal energy density of 242.7 Wh kg . This work provides valuable insights into developing high-energy and power-density cathode materials for SIBs.
钠离子电池（SIBs）被广泛认为是锂离子电池技术的一种有前景的替代方案。然而，它们仍然面临挑战，如倍率性能低、循环稳定性不理想以及变温性能较差。在本研究中，成功构建了一种分级的NaV(PO)F（NVPF）@还原氧化石墨烯（rGO）/碳纳米管（CNT）复合材料（NVPF@rGO/CNT）。这种复合材料的特点是0D的NaV(PO)F纳米颗粒被由2D的rGO和1D的CNT组成的交联3D导电网络包覆。此外，通过综合表征揭示了NVPF@rGO/CNT的本征储钠机制。合成的NVPF@rGO/CNT在宽工作温度（-40至50°C）范围内表现出快速的离子/电子传输和优异的结构稳定性，这归因于零应变的NVPF以及包覆的rGO/CNT导电网络，该网络减少了离子和电子的扩散距离。此外，NVPF与rGO/CNT之间的稳定结合实现了出色的结构稳定性，以减轻循环过程中产生的应变和应力。此外，采用硬碳阳极与NVPF@rGO/CNT阴极组装了一个实用的全电池，该全电池在0.2C时提供了105.2 mAh g的良好容量，从而实现了242.7 Wh kg的理想能量密度。这项工作为开发用于SIBs的高能量和功率密度阴极材料提供了有价值的见解。
