A Novel Titanium/Manganese Redox Flow Battery

Abstract

In this paper we report a novel redox flow battery using a titanium and manganese mixed solution as both positive and negative electrolytes. Ti(IV) ions existing in positive electrolyte suppress the Mn(III) disproportionation reaction, as well as particle growth of Mn dioxides. The energy density of 23.5 kWh m-3 was obtained in a single cell test, which is comparable to that of all-vanadium RF battery. Mn dioxide nanoparticles contribute to excellent flowablity and electro-active performance. In the cycling stability test, the performance is stable over more than 40 cycles. It is considered that the same electrolyte in both half-cells prevent mixing of electro-active species.

Hydrogen/manganese hybrid redox flow battery

“…Visual observation of the stability of electrochemically generated Mn 3+ in the presence of different metal ion species showed increasing stability in the order Al 3+ <TiO 2 2+ <Ti 4+ . These results are well aligned with recent development of electrolytes for liquid-liquid RFB architectures [14,15]. Electrochemical measurement of voltammetry of solutions of MnSO 4 in H 2 SO 4 in the presence and absence of Ti(SO 4 ) 2 showed increased electrochemical reversibility and the absence of a 'nucleation loop' (indicative of nucleation and growth of a solid phase [25]) when the titanium species was present in solution (see supplementary figure 2).…”

“…The Mn(III)/Mn(II) redox couple offers a high standard redox potential (E 0 =1.51 V), low cost and high solubility which encourages the development of Mn-based energy storage technologies for large scale applications. Very few studies dealing with soluble aqueous manganese formulations for RFB applications have been reported to date [13][14][15]. During battery charging, Mn(III) is produced and in an aqueous environment this species quickly undergoes a disproportionation reaction to yield soluble Mn(II) and MnO 2 as a precipitate (equation 1) [16].…”

“…Use of metal additives [14,23] has shown some promise as well. This paper demonstrates the benefits of merging a hybrid RFB architecture (which utilizes H 2 as negative electrode reactant) and the use of earthabundant redox couples (stable Mn(III) complexes in acidic conditions).…”

Repurposing the Industrial Dye Methylene Blue as an Active Component for Redox Flow Batteries

“…Using the reported solubility of 0.1 M for MB and a theoretical open circuit voltage of 1 V for a RFB system paired with a well‐established redox couple such as Mn 3+/2+ , an energy density of 9.6 kJ/L is estimated. This is on the low end but on par with other emerging systems of interest.…”

Vanadium–Manganese Redox Flow Battery: Study of MnIII Disproportionation in the Presence of Other Metallic Ions

“…For the minimization of the issues related to disproportionation reaction, higher sulfuric acid concentration up to 6 m and/or addition of Ti IV (TiO 2+ ) to the manganese electrolyte have been shown to stabilize Mn III . Hence, the equilibrium of the disproportionation reaction was displaced and the morphology of the manganese oxide particles modified . Tokuda et al.…”