Amorphous NaVOPO ₄ as a High-Rate and Ultrastable Cathode Material for Sodium-Ion Batteries

Abstract

The low cost and profusion of sodium resources make sodium-ion batteries (SIBs) a potential alternative to lithium-ion batteries for grid-scale energy storage applications. However, the use of conventional cathode materials for Na-ion intercalation/ deintercalation cannot satisfy the requirements of high-powered and long lifespan performance due to multiphase transition and lattice confinement. Herein, we demonstrate that amorphous NaVOPO 4 incorporated reduced graphene oxide hybrid in a SIB is a superior cathode with high-rate performance and stable cycle life. Remarkably, the electrode exhibits high voltage (∼3.5 V vs Na/Na + ), high reversible capacity (110 mAh g −1 at 0.05 C), and remarkable cyclability with 96% capacity retention over 2000 cycles. This outstanding performance originates from its amorphous characteristics and the unique hierarchical microflower structure of the hybrid, which undergo a distinct single-phase-like redox reaction without lattice restriction during charge/ discharge processes, thus accelerating the intercalation/deintercalation of large-sized Na + ions and maintaining the integrity and stability of the microflower cathode. This amorphous cathode material with fast ion migration and high structural stability may open a new avenue for exploring advanced electrode materials for efficient sodium storage.

Nitrogen‐Doped Amorphous Zn–Carbon Multichannel Fibers for Stable Lithium Metal Anodes

“…Raman spectra show the typical D and G bands of carbon in both Zn‐CMFs and CC‐Zn‐CMFs (Figure 2 m). [43, 44] As disclosed by thermogravimetric analysis, the weight contents of Zn nanoparticles in the Zn‐CMFs and CC‐Zn‐CMFs are about 23.9 and 20.5 wt %, respectively (Figure 2 n). Nitrogen adsorption/desorption isotherms reveal that the CC‐Zn‐CMFs composite has a mesoporous structure with a higher Brunauer–Emmett–Teller (BET) surface area (74.7 m 2 g −1 ) compared to the Zn‐CMFs (61.8 m 2 g −1 ; Figure 2 o).…”

Nitrogen‐Doped Amorphous Zn–Carbon Multichannel Fibers for Stable Lithium Metal Anodes

“…Raman spectra show the typical D and G bands of carbon in both Zn-CMFs and CC-Zn-CMFs (Figure 2 m). [43,44] As disclosed by thermogravimetric analysis, the weight contents of Zn nanoparticles in the Zn-CMFs and CC-Zn-CMFs are about 23.9 and 20.5 wt %, respectively (Figure 2 n). Nitrogen adsorption/desorption isotherms reveal that the CC-Zn-CMFs composite has a mesoporous structure with a higher Brunauer-Emmett-Teller (BET) surface area (74.7 m 2 g À1 ) compared to the Zn-CMFs (61.8 m 2 g À1 ; Figure 2 o).…”

Rational Design and Engineering of One‐Dimensional Hollow Nanostructures for Efficient Electrochemical Energy Storage

“…The uneven distribution of lithium resources in the world and their ever‐increasing price have stimulated the battery community to explore alternative battery technologies that are cost‐effective and offer comparable electrochemical properties. SIBs have aroused growing attention in recent years because of the low cost and wide profusion of sodium resources, as well as their similar chemical/electrochemical properties as well‐developed LIBs [75–77] . In recent years, great achievements have been obtained by exploring different advanced electrode materials.…”