Synthesis and Electrochemical Characterization of NaCoO₂ as Cathode Material in 2 M NaOH Aqueous Electrolyte

Abstract

This work reports an electro‐analytical study of NaCoO2 as cathode material synthesized by a low‐temperature combustion method for aqueous sodium‐ion batteries. The synthesized cathode material was electrochemically characterized in 2 M NaOH aqueous electrolyte. The obtained material‘s physical characteristics are investigated by X‐Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X‐ray analysis (EDX), Thermo‐Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) to evaluate its crystal structure, crystal size, composition, and surface morphology. From SEM images, the crystal size of the synthesized NaCoO2 is found to be varying between 50–100 nm with good crystallinity. From TGA studies, the material shows thermal stability up to around 300 °C with maximum weight loss at about 375 °C. Electrochemical behaviour of NaCoO2 in 2 M aqueous sodium electrolytes are evaluated using cyclic voltammetry and galvanostatic charge‐discharge techniques. The cell, NaTi2(PO4)3/2 M NaOH/NaCoO2 constructed in aqueous 2 M NaOH is found to deliver a discharge capacity of 89 mAh g−1 at C/10 rate. It retains its initial capacity over 55 cycles and at a high Crate of 1 C a discharge capacity of 34 mAh g−1 was obtained which can be compared with that obtained for NaCoO2 in non‐aqueous battery systems.

Synthesis of Flower-Like, Hyperbranched Na3FePO4CO3 Nanocrystals and Their Electrochemical Performance as Cathodes in Aqueous Rechargeable Sodium-Ion Batteries

“…The XRD pattern of NaTi 2 (PO 4 ) 3 anode material has been reported in our work previously. 13 The surface morphology and structure of the material was determined using scanning electron microscope (SEM). Figures 3A-3D show typical SEM image of NFPC at different magnifications, i.e., 2 μm, 1 μm, 500 nm and 200 nm respectively.…”

“…Initially, in ARSBs, layered transition metal oxides (LTMO) were introduced and studied their Na + insertion/de-insertion properties. [8][9][10][11] Recent studies in ARSBs showed successive result with P2-Na 0.57 CoO 2 , 12 NaCoO 2 , 13 Na 4 MnV(PO 4 ) 3 -rGO, 14 Na 4 Mn 9 O 18 / reduced grapheme oxide (NMO-RGO). 15 Despite of having these success stories of sodium-based aqueous rechargeable batteries, there is an increased concern on improving the energy storage capacity of the ARSBs.…”

Partial Modification Strategies of NASICON-Type Na3V2(PO4)3 Materials for Cathodes of Sodium-Ion Batteries: Progress and Perspectives

“…), conversion-based materials (oxygen-, phosphor-, sulfur-, and selenium-based materials, for example, MS x with M = Sn, Sb, Mo, Fe, Co, Ni, Mn), and alloying-based materials (e.g., Si, Ge, Sn, Sb, and Bi). 22−25 There are also different types of SIB cathode materials according to structure classification: twodimensional layer transition metal oxide, Na 1−x MO 2 (M = Fe, 26 Ti, 27 Co, 28 V, 29 Ni, 30 etc. ), 31 two-or three-dimensional layer transition metal oxide and fluorides (such as NaFeF 3 , 32 NaNiF 3 , 33 etc.…”

“…According to the reaction mechanism, the anode can be divided into three types: insertion-based materials (including titanium-based oxide and carbonaceous materials, such as TiO 2 , graphene, soft carbon (SC), hard carbon (HC), etc. ), conversion-based materials (oxygen-, phosphor-, sulfur-, and selenium-based materials, for example, MS x with M = Sn, Sb, Mo, Fe, Co, Ni, Mn), and alloying-based materials (e.g., Si, Ge, Sn, Sb, and Bi). − There are also different types of SIB cathode materials according to structure classification: two-dimensional layer transition metal oxide, Na 1– x MO 2 (M = Fe, Ti, Co, V, Ni, etc. ), two-or three-dimensional layer transition metal oxide and fluorides (such as NaFeF 3 , NaNiF 3 , etc.…”