Work

Ternary Na 3 V 2 (PO 4 ) 3 /Na 3 V 2 (PO 4 ) 2 F 3 /NaV(P 2 O 7 ) Heterogeneous Structure with Interactive Built‐in Electric Field Enables Advanced Sodium Storage Performance

Year: 2025

Type: article

Abstract: Traditional polyanion cathode suffers from the poor electronic and ionic transportation. Low capacity and energy seriously hinders its further development. Herein, konjac glucomannan (KGM) acts as inducer to synthesize ternary Na 3 V 2 (PO 4 ) 3 /Na 3 V 2 (PO 4 ) 2 F 3 /NaV(P 2 O 7 ) heterogeneous cathode (NVP@KGM/F‐10%). The detailed formation mechanism is clearly revealed by ex‐situ high‐temperature XRD. The multispatial Na sites in NVP@KGM/F‐10% is investigated by NMR, further demonstrating the co‐existence of ternary cathodes. XAFS ensures the elongated V‐O bond, which constructs a lager framework for accelerated Na + migration. Moreover, NVP@KGM/F‐10% possesses a unique columnar porous morphology with a high specific surface area of 84.53 m 2 g −1 , facilitating the electrolyte immersion. Ex‐situ XRD/XPS reveal the charge compensation mechanism of NVP@KGM/F‐10% and elaborate the stability effects of C‐F bond. Significantly, due to the difference of work function and band gap among Na 3 V 2 (PO 4 ) 3 /Na 3 V 2 (PO 4 ) 2 F 3 /NaV(P 2 O 7 ), three interactive built‐in electric fields are constructed at the heterogeneous interfaces, directly promoting the kinetics inside the NVP@KGM/F‐10% electrode, which has been verified by DFT calculations and experimental characterizations. Notably, the DOS of Na 3 V 2 (PO 4 ) 3 /Na 3 V 2 (PO 4 ) 2 F 3 /NaV(P 2 O 7 ) heterostructures and energy barriers between the heterogeneous interface are also evaluated by DFT, further demonstrating the great superiority of ternary heterogeneous structure. This work provides guidance for designing multiple phases heterogeneous cathodes with advanced properties.

Source: Advanced Functional Materials

DOI: 10.1002/adfm.202511984

Authors: Shuming Zhang, Tao Zhou, Yuelei Pan, Hongen Shi, Yanjun Chen

Institutions: North University of China, University of Science and Technology of China, State Key Laboratory of Fire Science

Language: English

Topic: Advancements in Battery Materials

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: bronze

Funder: National Natural Science Foundation of China