Porous Amorphous FePO4Nanoparticles Connectedby Single-Wall Carbon Nanotubes for Sodium Ion Battery Cathodes.

Sodium ion batteries (SIBs) are promising candidatesfor the applicationsof large-scale energy storage due to their cost-effective and environmental-friendlycharacteristics. Nevertheless, it remains a practical challenge tofind a cathode material of SIBs showing ideal performance (capacity,reversibility, etc.). We report here a nanocomposite material of amorphous,porous FePO4nanoparticles electrically wired by single-wallcarbon nanotubes as a potential cathode material for SIBs. The hydrothermallysynthesized nanocomposite shows excellent cell performance with unprecedentedcycling stability and reversibility. The discharge capacity of ashigh as 120 mAh/g is delivered at a 0.1 C rate (10 mA/g). The capacityretentions are about 70 mAh/g, 60 mAh/g, and 55 mAh/g at higher currentsof 20 mA/g, 40 mA/g, and 60 mA/g, respectively. Even at a 1 C rate(100 mA/g), a capacity of about 50 mAh/g is still retained after 300cycles. With a simple synthetic procedure, cost-effective chemicals,and desirable cell performance, this method offers a highly promisingcandidate for commercialized cathode materials of SIBs. [ABSTRACT FROM AUTHOR]