Park Seungman, Kim Chae Won, Lee Kyu Sang, Hwang Seon Jae, Piao Yuanzhe
Graduate School of Convergence Science and Technology, Seoul National University, 145 Gwanggyo-ro, Yeongtong-gu, Suwon-Si, Gyeonggi-do, 16229, Republic of Korea.
Advanced Institutes of Convergence Technology, 145 Gwanggyo-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do, 16229, Republic of Korea.
Nanoscale. 2023 Sep 1;15(34):14155-14164. doi: 10.1039/d3nr02652c.
Developing a facile strategy which enhances the structural stability and air/moisture stability of transition metal phosphides for practical applications is important but challenging. Herein, we designed a densely packed free-standing film consisting of carbon-coated FeP nanoparticles anchored on P-doped graphene (FeP@C@PG film) through solventless thermal decomposition and the roll-press method. Phytic acid serves a multifunctional role as both a phosphorus source to prepare ultrafine FeP nanoparticles and a protective layer to improve air stability along with hydrophobic graphene and maximize the utilization of phosphide. This structure can enhance electron/ion transport kinetics, allowing for full utilization of active materials, and buffer large volume expansions while preventing pulverization/aggregation during cycling. Noticeably, the densely packed structure can greatly enhance oxidation resistance by effectively blocking the penetration of air/moisture. Therefore, the FeP@C@PG film delivers a stable reversible capacity of 536.6 mA h g after 1000 cycles at 1 A g with good capacity retention, an excellent rate capability of 440.7 mA h g at 5 A g, and excellent oxidation stability at 80 °C in air. Furthermore, a pouch-type full-cell exhibits excellent rate/cycling performance and bendability. This study provides a new direction for the rational design and practical applications of advanced P-based materials used in alkali metal-ion batteries.
开发一种简便的策略以提高过渡金属磷化物在实际应用中的结构稳定性和空气/湿气稳定性是重要但具有挑战性的。在此，我们通过无溶剂热分解和辊压法设计了一种由锚定在P掺杂石墨烯上的碳包覆FeP纳米颗粒组成的紧密堆积的独立薄膜（FeP@C@PG薄膜）。植酸起着多功能作用，既是制备超细FeP纳米颗粒的磷源，又是与疏水性石墨烯一起提高空气稳定性并最大化磷化物利用率的保护层。这种结构可以增强电子/离子传输动力学，使活性材料得到充分利用，并缓冲大体积膨胀，同时防止循环过程中的粉化/聚集。值得注意的是，紧密堆积的结构可以通过有效阻挡空气/湿气的渗透大大提高抗氧化性。因此，FeP@C@PG薄膜在1 A g下循环1000次后具有536.6 mA h g的稳定可逆容量和良好的容量保持率，在5 A g下具有440.7 mA h g的优异倍率性能，以及在80°C空气中的优异氧化稳定性。此外，软包型全电池表现出优异的倍率/循环性能和可弯曲性。这项研究为碱金属离子电池中先进的磷基材料的合理设计和实际应用提供了新方向。
