Flow channel optimisation of iodine zinc flow battery modelling

Figures & data

Figure 1. Equivalent circuit model of the iodine zinc flow battery.

Figure 2. Hybrid model block diagram of the iodine zinc flow battery.

Figure 3. Parallel hydraulic resistance network model.

Figure 4. Flow chart of multiple optimisation of the flow channel.

Figure 5. Multi-channel serpentine flow channel on the opposite side of double baffles.

Table 1. Basic geometric dimensions of the iodine zinc flow battery bipolar plate (mm).

Subassembly	Bipolar plate		Reaction region		Main channel		Tributary channel
Dimension	Length	width	length	width	length	width	Groove width	Ridge width	Groove depth
	176	126	134	92	114	10	4	4	2

Figure 6. The grid diagram of the multi-channel serpentine flow channel on the opposite side of the double baffles.

Figure 7. Flow distribution of tributaries with different flow channel structures.

Figure 8. Flow and velocity distribution diagram of the multi-channel serpentine flow channel.

Figure 9. Flow and velocity distribution of multi-channel serpentine flow channel on the opposite side of the double baffles.

Table 2. Error analysis of electrolyte flow uniformity at different baffle tilt angles.

Baffle tilt angle (degrees)	Maximum error of simulation $R$ (%)	Ideal maximum error $r$(%)
2.56	8.36	5.53
3.86	7.46	4.65
5.71	5.55	2.21
7.62	6.56	3.26
9.56	6.78	3.66
11.24	6.89	3.86
15.56	6.67	3.34
18.32	6.72	3.46

Figure 10. Change of pump loss current during charging and discharging of iodine zinc flow battery in different channels.

Figure 11. Experimental test equipment. 1. Microcomputer, 2. Tester, 3. Constant temperature test chamber, 4. Zinc iodide positive electrolyte, 5. Iodine zinc flow battery stack, 6. Negative electrolyte, 7. Circulating pump.

Figure 12. Three-dimensional structure diagram of the flow battery stack.

Figure 13. (a) Flow guide plate (b) Stack structure.

Figure 14. Bipolar plate for carbon material and metal material composite.

Table 3. Summary of chemical reagents and raw materials used in the experiment.

Material name	Material size/model
Bipolar plate (copper)	$200\ast 1000\ast \mathrm{m}{\mathrm{m}}^3$
Bipolar plate (graphite plate)	$200\ast 250\ast 0.6\mathrm{mm}$
Carbon felt electrode	$100\ast 100\ast 5$
Zinc sheet	$0.05\ast 100\ast 110\mathrm{m}{\mathrm{m}}^3$
Zinc iodide	$200\mathrm{g}$
Ion exchange membrane	$200\mathrm{mm}\ast 200\mathrm{mm}(\mathrm{Nafion}115)$
Speed-regulating peristaltic pump	$\mathrm{BT}100-02$
Intelligent speed control peristaltic pump	$\mathrm{KSP}-\mathrm{F}01\mathrm{A}$

Figure 15. (a) Battery test system BT-2018R (b) SPX-50 constant temperature test chamber.

Figure 16. V-t change curve of charge and discharge in multi-channel serpentine flow channel on the opposite side of double baffles of iodine zinc flow battery.

Figure 17. V-t change curve of traditional straight parallel flow channel charge and discharge of the iodine zinc flow battery.

Figure 18. Change of pump loss current during charging and discharging of double baffle multi-channel serpentine channel of the iodide zinc flow battery.