The growing demand for renewable energy has increased the need to develop large-scale energy storage systems that can be deployed remotely in decentralised and deregulated networks. Vanadi.
What is a flow battery?
Flow batteries allow for independent scaleup of power and capacity specifications since the chemical species are stored outside the cell. The power each cell generates depends on the current density and voltage. Flow batteries have typically been operated at about 50 mA/cm 2, approximately the same as batteries without convection.
Does electrolyte flow rate affect battery performance?
The battery was tested to assess its performance; it achieved a coulombic efficiency of 97%, a voltage efficiency of 74.5% and an energy efficiency of 72.3%. The battery was used to study the effect of electrolyte flow rate on the overall performance. The results indicated that an increased flow rate increased the capacity.
What is the difference between power and capacity of a flow battery?
The capacity is a function of the amount of electrolyte and concentration of the active ions, whereas the power is primarily a function of electrode area within the cell. Similar to lithium-ion cells, flow battery cells can be stacked in series to meet voltage requirements. However, the electrolyte tanks remain external to the system.
Does flow rate affect battery power?
The flow rate of the battery directly affects the pressure losses that occur and, by extension, the power that the pumps must provide for the battery to operate. However, as studies such as Ref. 20 have reported, flow rate also influences battery voltage and shunt currents, thus affecting the battery power.
Linking with Eq. 22, the higher the current, the greater the flow rate needed; therefore, the pressure losses will increase, implying a higher need for pump power. This probably directly limits the value of the flow factor. Knowing the optimum flow factor for battery operation is of great interest to optimize battery efficiency.
Effect of variable flow rate on capacity Despite the increased battery capacity that can be achieved at high flow rates, greater levels of pumping reduce the overall efficiency of the system (battery, pumps and tubings).