§Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 CleanTech Loop, 637141, Singapore.
†School of Energy and Environment, Anhui University of Technology, Maanshan, Anhui 243002, China.
ACS Nano. 2015 Apr 28;9(4):4628-35. doi: 10.1021/acsnano.5b00932. Epub 2015 Apr 15.
Metal vanadium phosphates (MVP), particularly Li3V2(PO4)3 (LVP) and Na3V2(PO4)3 (NVP), are regarded as the next-generation cathode materials in lithium/sodium ion batteries. These materials possess desirable properties such as high stability, theoretical capacity, and operating voltages. Yet, low electrical/ionic conductivities of LVP and NVP have limited their applications in demanding devices such as electric vehicles. In this work, a novel synthesis route for the preparation of LVP/NVP micro/mesoporous 3D foams via assembly of elastin-like polypeptides is demonstrated. The as-synthesized MVP 3D foams consist of microporous networks of mesoporous nanofibers, where the surfaces of individual fibers are covered with MVP nanocrystallites. TEM images further reveal that LVP/NVP nanoparticles are about 100-200 nm in diameter, with each particle enveloped by a 5 nm thick carbon shell. The MVP 3D foams prepared in this work exhibit ultrafast rate capabilities (79 mA h g(-1) at 100C and 66 mA h g(-1) at 200C for LVP 3D foams; 73 mA h g(-1) at 100C and 51 mA h g(-1) at 200C for NVP 3D foams) and excellent cycle performance (almost 100% performance retention after 1000 cycles at 100C); their properties are far superior compared to current state-of-the-art active materials.
金属钒磷酸盐（MVP），尤其是 Li3V2(PO4)3（LVP）和 Na3V2(PO4)3（NVP），被认为是下一代锂离子/钠离子电池的正极材料。这些材料具有高稳定性、高理论容量和高工作电压等理想特性。然而，LVP 和 NVP 的低电导率和离子电导率限制了它们在电动汽车等要求苛刻的设备中的应用。在这项工作中，通过弹性蛋白样多肽的组装，展示了一种制备 LVP/NVP 微/介孔 3D 泡沫的新方法。所合成的 MVP 3D 泡沫由介孔纳米纤维的微孔网络组成，其中纤维的表面覆盖有 MVP 纳米晶。TEM 图像进一步表明，LVP/NVP 纳米颗粒的直径约为 100-200nm，每个颗粒都被 5nm 厚的碳壳包裹。本工作制备的 MVP 3D 泡沫具有超快倍率性能（LVP 3D 泡沫在 100C 时为 79 mA h g(-1)，在 200C 时为 66 mA h g(-1)；NVP 3D 泡沫在 100C 时为 73 mA h g(-1)，在 200C 时为 51 mA h g(-1)）和优异的循环性能（在 100C 下循环 1000 次后，性能保持率几乎为 100%）；其性能远远优于当前的先进活性材料。
