Olchowka Jacob, Fang Runhe, Bianchini Nuernberg Rafael, Pablos Chloé, Carlier Dany, Cassaignon Sophie, Croguennec Laurence
Univ. Bordeaux, CNRS, Bordeaux INP, ICMCB, UMR 5026, F-33600 Pessac, France.
RS2E, Réseau Français sur le Stockage Electrochimique de l'Energie, CNRS 3459, 80039 Amiens Cedex 1, France.
Nanoscale. 2022 Jun 23;14(24):8663-8676. doi: 10.1039/d2nr01080a.
NaV(PO)FO is a promising candidate for practical use as a positive electrode material in Na-ion batteries thanks to its high voltage and excellent structural stability upon cycling. However, its limited intrinsic transport properties limit its performance at fast charge/discharge rates. In this work, two efficient approaches are presented to optimize the electrical conductivity of the electrode material: particle nanosizing and particle coating with an ionic liquid (IL). The former reveals that particle downsizing from micrometer to nanometer range improves the electronic conductivity by more than two orders of magnitude, which greatly improves the rate capability without affecting the capacity retention. The second approch dealing with an original surface modification by applying an IL coating strongly enhances the ionic mobility and offers new perspectives to improve the energy storage performance by designing the electrode materials' surface composition.
由于其高电压以及循环过程中出色的结构稳定性，NaV(PO)FO是一种很有前景的可实际用作钠离子电池正极材料的候选物。然而，其固有的传输性能有限，限制了其在快速充放电速率下的性能。在这项工作中，提出了两种优化电极材料电导率的有效方法：颗粒纳米化和用离子液体（IL）包覆颗粒。前者表明，将颗粒尺寸从微米级减小到纳米级可使电子电导率提高两个多数量级，这在不影响容量保持率的情况下极大地提高了倍率性能。第二种方法是通过应用IL包覆进行原始表面改性，这极大地增强了离子迁移率，并为通过设计电极材料的表面组成来提高储能性能提供了新的视角。
