Acid/base flow battery environmental and economic performance based on its potential service to renewables support

How Green are Redox Flow Batteries?

“…[46] In the case of an AB-FB, the phase contributing the most to the total impacts is also the use phase (referred to as operations and maintenance), which can be attributed to the electricity losses generated when the battery is serviced to support wind and PV installations. [58] The end-of-life contribution to the total impacts is rather minor as compared to the other stages, [23,58] except for the impact category of freshwater eutrophication potential in case of VRFB and ZBFB, as well as in the case of IFB systems where the waste treatment accounts for 84-88 % of the impacts. [53] In most cases, however, this phase only makes a small contribution to the overall impacts, but substantial reductions can be made by the recycling of materials and components.…”

“…assumed that just 90 % of metal and plastic mass recovered from the ESS site would enter the recycling process, and a 100 % recycling efficiency for steel and copper (incl. the required energy input to recycle) was assumed by Díaz‐Ramírez et al [58] . Two studies based their assumptions on the work of Rigamonti et al., [73] who assumed a recycling efficiency of 81.45 % for steel, 55.71 % for plastic and 79.33 % for copper [45,59] .…”

“…However, we found no information in this study regarding how the analysis was performed in detail. Other research groups addressed uncertainty with respect to normative choices by performing a sensitivity analysis, for example, to examine the ESS energy demand/mix and efficiencies, [23,24,42,46,47,51,56,58] possibilities of cell degradation, [51] performance measurements like energy/power ratios, [44,55,57] battery life time, [46] usable storage capacity, [41,46] share/use of secondary materials, [23,41,44,46] transportation, [52] or alternative materials for certain components like different chemical compositions of mesh and membrane materials. [23,50,[55][56][57]…”

“…Vanadium RFB is the technology that was most often investigated in the reviewed literature (91 %). The components of a VRFB can be grouped into power subsystem components (e. g., electrodes, membranes, bipolar plates), energy subsystem components (electrolyte and the tank), and periphery components (e. g., pumps, motors, racks) [45,50,58] . Depending on the specific energy of the electrolyte (Table 2) or the energy capacity of the VRFB, the energy subsystem makes up a high share of the total weight (70–90 %) [23,41,45,50,58] .…”

“…Although the sustainability of VRFBs have been studied to some extent, emerging flow battery types such as organic aqueous and non-aqueous flow batteries have not yet been systematically investigated, with the exception of acid-base flow batteries. [58] Nevertheless, the abundance and facile modification of organic molecules in nature make them potential candidates as active materials in flow battery technology systems. [81,82] In addition, decomposition mechanisms and other properties can be studied by using a wide range of analytical and computational methods.…”