Research Progress on Electrochemical Properties of Na<sub>3</sub>V<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub> as Cathode Material for Sodium-Ion Batteries
Fa He, Jiyang Kang, Tongli Liu, Hongjie Deng, Benhe Zhong, Yan Sun, Zhenguo Wu, Xiaodong Guo
Abstract
The polyanion sodium vanadium phosphate Na 3 V 2 (PO 4 ) 3 (NVP) belongs to the sodium superionic conductors (NASICON) material. Its NASICON structural backbone forms a stable sodium accommodation site, and the open three-dimensional ion transport channel is conducive to the rapid intercalation/deintercalation of Na ions. As a cathode material for batteries, Na 3 V 2 (PO 4 ) 3 has an extremely high specific capacity, voltage plateau, and cycle stability, meeting the requirements of low cost and high safety. It is a large-scale energy storage material with ideal potential and has received extensive attention. However, the low electronic conductivity of Na 3 V 2 (PO 4 ) 3 material hinders its further application. Based on the current demand for large-scale application of sodium-ion batteries, this paper re-examines the effect of existing research progress on promoting practical applications and the problems that need to be solved in the future from the perspective of raw material cost system and process complexity. The paper first introduces the structural characteristics of Na 3 V 2 (PO 4 ) 3 material and the mechanism of sodium-ion intercalation/deintercalation. Then it introduces the synthesis methods, such as the sol–gel method, hydrothermal method, and solid-phase reaction method. In addition, it summarizes the modification studies of Na 3 V 2 (PO 4 ) 3, including carbon coating, ion doping and, morphology control, design of composite materials and structures based on Na 3 V 2 (PO 4 ) 3 . Finally, it discusses the possible future development of Na 3 V 2 (PO 4 ) 3 .