Even though significant improvements have been made in sodium ion batteries, battery management mandates that all batteries in a pack are kept at an acceptable level of more than 80% capacity retention after a long cycle when it is tested for emergencies. Based on these realistic facts, the present study profitably exploits in situ grown reduced graphene oxide on 3D Na3V2 (PO4)3 matrices exhibiting a high rate performance and a specific discharge capacity of 117 mAh g-1. Unlike the earlier literature reports, it is demonstrated that the fabricated electrode shows >85% capacity retention after 6000 cycles at 10 C, the longest cycle life reported till date. The work also reasons in-depth the outstanding sodiation/desodiation capabilities to the low hysteresis voltage and how these electrodes can be used for deep discharges by extending the potential window to 1.3-3.8 V (vs Na/Na+) resulting in a noteworthy specific capacity of ≈165.4 mAh g-1 at 1 C.
Available for download on Friday, March 31, 2017