Synthesis and Characterizations of Na4MnCr(PO4)3/rGO as NASICON-Type Cathode Materials for Sodium-ion Batteries

Bing-Hsuan Hsu; Wei-Ren Liu

doi:10.3390/polym14194046

Synthesis and Characterizations of Na₄MnCr(PO₄)₃/rGO as NASICON-Type Cathode Materials for Sodium-ion Batteries

Polymers (Basel). 2022 Sep 27;14(19):4046. doi: 10.3390/polym14194046.

Authors

Bing-Hsuan Hsu¹, Wei-Ren Liu¹

Affiliation

¹ Department of Chemical Engineering, R&D Center for Membrane Technology, Center for Circular Economy, Chung Yuan Christian University, 200 Chung Pei Road, Chungli District, Taoyuan City 320, Taiwan.

Abstract

NASICON-type Na₄MnCr(PO₄)₃ (NMCP) wrapped with reduced graphene oxide (rGO) was synthesized via a simple sol-gel method as composite cathode material Na₄MnCr(PO₄)₃/rGO (NMCP/rGO) for Na ion batteries. The surface morphology, crystal structure and pore size distribution of pristine NMCP and as-synthesized NMCP/rGO composite cathode are identified by X-ray diffraction (XRD), field emission-scanning electron microscopy (SEM), transmission electron microscope (TEM), the Brunauer-Emmett-Teller (BET) method and X-ray photoelectron spectroscopy (XPS). The electrochemical performance of composition-optimized NMCP/rGO composite cathode presents stable capacity retention and rate capability. The capacity retention of as-synthesized NMCP/rGO composite is 63.8%, and average coulombic efficiency maintains over 98.7% for 200 cycles. The reversible capacity of as-synthesized NMCP/rGO composite cathode still retained 45 mAh/g and 38 mAh/g under a current density of 0.5 A/g and 1.0 A/g, respectively, which was better than that of pristine NMCP, with only 6 mAh/g and 4 mAh/g. The redox reactions of pristine NMCP and as-synthesized NMCP/rGO composite are studied via cyclic voltammetry. The improved electronic conductivity and structure stability of bare NMCP is attributed to the contribution of the rGO coating.

Keywords: NASICON; Na4MnCr(PO4)3; cathode; reduced graphene oxide; sodium ion battery.

Grants and funding

This research was funded by the Ministry of Science and Technology [MOST 110-2811-E-033-505, 110-2622-M-033-001, 110-2622-E-033-009, 110-2923-E-006-011, 108-E-033-MY3, 110-3116-F-011-002 and 111-2221-E-033-004-MY3].