Highly Reversible and Ultrafast Sodium Storage in NaTi₂(PO₄)₃ Nanoparticles Embedded in Nanocarbon Networks

Sodium ion batteries (NIBs) have been considered as an alternative for Li ion batteries (LIBs). NaTi2(PO4)3 (denoted as NTP) is a superior anode material for NIBs. However, the poor electrochemical performance of NTP resulting from the low electronic conductivity prevents its application. Here, NTP nanoparticles embedded in carbon network (denoted as NTP/C) were fabricated using a simple soft-template method. This anode material exhibits superior electrochemical performance when used as anode electrodes for NIBs, including highly reversible capacity (108 mAh g(-1) at 100 C) for excellent rate performance and long cycle life (83 mAh g(-1) at 50 C after 6000 cycles). The excellent sodium storage property can be resulted from the synergistic effects of nanosized NTP, thinner carbon shell and the interconnected carbon network, leading to the low charge transfer resistance, the large surface area for electrolyte to soak in and enough void to buffer the volume variation during the repeated cycle.