Investigating Architectured Na<sub>3</sub>V<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub>/C/CNF Hybrid Cathode in Aqueous Zinc Ion Battery
Tong Xu, Mingshu Zhao, Su Zhou, Zheng Li, Vilas G. Pol, C. C. H. Lo
Abstract
Aqueous zinc ion batteries (AZIBs) have been attracting significant attention as promising next-generation electrical energy storage (EES) devices due to their low cost and intrinsically high thermal safety. Identifying suitable electrode materials is regarded as the key to constructing high-performance AZIB full cells. NASICON-type Na3V2(PO4)3 (NVP) material possesses an open three-dimensional structure and can reversibly accommodate zinc ion intercalation. Here, we develop a hybrid carbon coated NVP interconnected with carbon nanofibers (NVP/C/CNF) as an AZIB cathode. Cyclic voltammogram analysis shows that, after the addition of CNF, the electrode material possesses a higher Zn2+ diffusion coefficient with reduced electrochemical polarization. The NVP/C/CNF composite exhibits a reversible capacity of 95.1 mAh g–1 at 100 mA g–1, higher than NVP/C composite (77.3 mAh g–1). The uniform amorphous carbon alleviates vanadium dissolution during cycling, while the CNF network further increases the electrical conductivity and structural stability of the hybrid, which can effectively suppress the material’s irreversible deformation caused by deep and rapid intercalation of Zn2+. Therefore, the NVP/C/CNF composite cathode features a higher capacity retention (75.6% after 100 cycles) than NVP/C (63.1%). As verified, NVP/C/CNF is expected to be a great potential electrode in next-generation AZIBs.