**Conflict of interest**

There is no conflict of interest to be declared.

*Effects of Electrolyte Additives on Nonaqueous Redox Flow Batteries DOI: http://dx.doi.org/10.5772/intechopen.88476*

*Redox*

**6. Conclusions**

unchanged.

**Acknowledgements**

**Conflict of interest**

SbCl3. The results suggest that the enhancement of the battery performance is owing to the catalytic effect of Sb ions. However, when the concentration was 20 mM, the accumulation of ions is more serious, which would result in partial pore blockage of graphite felt. Therefore, when the concentration of Sb3+ ions further increases, the

The effects of three kinds of additives including carbon dioxide gas, EC/DMC, and Sb3+ ions on the electrochemical performance of nonaqueous DES electrolyte redox flow batteries are explored. The ohmic resistance of the deep eutectic solvent (DES) electrolyte decreases significantly when adding carbon dioxide gas and EC/ DMC, and the percentage of reduction increases with the volume percentage of EC/ DMC in electrolyte, while for these two additives, the reaction kinetics almost keeps

With CO2 in DES, the electrochemical reaction resistance increases about 10%. For EC/DMC additive, the electrochemical reaction resistance almost keeps the same no matter the amount of additive in electrolyte. For the additive of Sb3+ ions in DES electrolyte, the electrochemical reaction kinetics of active redox couple is enhanced, the diffusion coefficient of active ions increases, and the charge transfer resistance decreases. The electrodeposited Sb3+ ions on electrode surface contribute a catalytic effect on the electrochemical reaction. However, due to the trade-off between the enhanced kinetics and reduced active surface area, the optimum concentration of Sb3+ ions is found to be 15 mM. In addition, the flow battery assembled with negative electrolyte containing Sb3+ ions exhibits 31.2% higher power density. The results in this chapter provide a simple yet effective approach to

electrochemical performance of the battery decreases slightly.

promote the cell performance of nonaqueous redox flow batteries.

The work described in this chapter was fully supported by grants from the NSFC, China (No. 51676092 and No. 21676126), Six Talent Peaks Project in Jiangsu Province (2016-XNY-015), and a project funded by the Priority Academic Program

Development (PAPD) of Jiangsu Higher Education Institutions, China.

There is no conflict of interest to be declared.

**86**
