Enhanced Electrochemical Properties of Na0.67MnO2 Cathode for Na-Ion Batteries Prepared with Novel Tetrabutylammonium Alginate Binder

Abstract

Both the binder and solid–electrolyte interface play an important role in improving the cycling stability of electrodes for Na-ion batteries. In this study, a novel tetrabutylammonium (TBA) alginate binder is used to prepare a Na0.67MnO2 electrode for sodium-ion batteries with improved electrochemical performance. The ageing of the electrodes is characterized. TBA alginate-based electrodes are compared to polyvinylidene fluoride- (PVDF) and Na alginate-based electrodes and show favorable electrochemical performance, with gravimetric capacity values of up to 164 mAh/g, which is 6% higher than measured for the electrode prepared with PVDF binder. TBA alginate-based electrodes also display good rate capability and improved cyclability. The solid–electrolyte interface of TBA alginate-based electrodes is similar to that of PVDF-based electrodes. As the only salt of alginic acid soluble in non-aqueous solvents, TBA alginate emerges as a good alternative to PVDF binder in battery applications where the water-based processing of electrode slurries is not feasible, such as the demonstrated case with Na0.67MnO2.

A 30‐year overview of sodium‐ion batteries

“…As bridges between active materials, conductive agents, and current collectors, binders can be categorized as organic (polyvinylidene difluoride [PVDF]) 160,345 and aqueous (sodium carboxymethyl cellulose [CMC], 342,346,347 polyacrylic acid [PAA], sodium alginate [SA] 160 ) systems. PVDF is the most frequently utilized organic binder.…”

Binder design strategies for cathode materials in advanced secondary batteries

“…In this case, a non-aqueous treatment of alginate was proposed. 168 Tetrabutylammonium (TBA) alginate was prepared and used in an Na 0.67 MnO 2 cathode. In addition to water, this TBA alginate can also use dimethyl sulfoxide, N , N -dimethylformamide, or other polar aprotic solvents containing TBA fluoride as the solvent.…”

A review of the degradation mechanisms of NCM cathodes and corresponding mitigation strategies

“…Most notably, layered P2-type or O3type Na2/3MO2 (M -transition metal) materials are among the highest capacity cathodes for sodium-ion batteries [288]. Like NCM materials, Na2/3MO2 materials also suffer from undesired transformations of the crystal lattice [289][290][291], irreversible anion redox reactions resulting in oxygen evolution [74,292,293], excessive CEI growth [294][295][296], microcrack formation [297] and dissolution of manganese in the low potential range [298]. It follows that the strategies to mitigate the degradation of Na2/3MO2 cathodes are also analogous.…”