New energy battery application status and its development analysis (III)

Vanadium Liquid Current battery

Introduction

With the increasing attention to energy issues worldwide, new energy battery technologies have gradually become the top priority of scientific research and industrial development in various countries under the background of energy transition and sustainable development. From traditional lithium-ion batteries to more forward-looking hydrogen fuel cells, liquid flow batteries, etc., different types of batteries have shown a wide range of application prospects in the fields of power storage and electric vehicles. However, there are also many challenges and limitations, such as energy density, cycle life, and cost. To better promote the development of new energy sources, this series will comprehensively evaluate the advantages, drawbacks, and application scenarios of each type of mainstream new battery technology, provide valuable references and guidance for researchers, industrial practitioners, promote continuous innovation in this field, and contribute to the sustainable development of global energy.

Main article

All-vanadium liquid-flow batteries use vanadium ions of different valence states as the active substances of the batteries, which overcomes the problem of cross-contamination of the liquid-flow battery electrolyte. Due to the advantages of separate design of battery energy and power, high safety, and long cycle life, it has become one of the most promising technologies for large-scale energy storage ^[1].

Vanadium batteries use vanadium ions of different valence states as the active substances of the electrolyte, which avoids the problem of cross-contamination between different ions. At the same time, the electrochemical reversibility between different valence states of vanadium ions is high and the polarization is small, which is suitable for fast charging and discharging with high current. Vanadium batteries are often used for grid peaking, large-scale photovoltaic and wind energy systems, and emergency power systems. Vanadium batteries are mainly composed of electrolyte, electric stack and circulation system. Researchers around the world are committed to using stable electrolyte composition, advanced electrode materials as positive and negative electrodes of batteries to improve and optimize the performance of vanadium batteries and reduce the cost of vanadium batteries.

However, all-vanadium liquid flow batteries also have certain defects. Firstly, the by-products require high treatment and produce V2O5, which is a highly toxic chemical. Secondly, the cost is high, the current 5kW vanadium battery only material cost can be more than 400,000 dollars. In addition, subject to the upper limit of ion solubility in the electrolyte, vanadium battery specific energy density is low, and the technology is difficult to breakthrough. The same energy vanadium battery volume can be up to 3-5 times the lithium battery, the mass of 2-3 times. Therefore, vanadium batteries can only be applied to static energy storage systems, and are difficult to be applied to electric vehicles, electronic products and other fields ^[2].

Due to the inherent advantages of all-vanadium flow batteries and a wide range of applications, they have attracted a great deal of attention in the world, and their industrialization has been raised to a strategic level of attention by western countries, and in some countries and regions, all-vanadium flow batteries have reached the level of commercial operation. In the future, the hotspots of all-vanadium flow battery research focus on improving the performance of electrode materials, developing low-cost, highly selective, long-life ion-exchange membranes and electrolytes with high concentration, high conductivity and high stability, improving the stability, specific energy and energy conversion efficiency of the battery, and promoting the industrialization of all-vanadium flow battery. In addition, it should also strengthen the research of vanadium ion electrode reaction kinetics, electrolyte theory, new diaphragm and other basic areas, so as to provide a more solid foundation for the research and development of all-vanadium liquid current battery. Constraints on the development of all-vanadium liquid current batteries are still the factor of high cost, especially the energy storage station can be used in the second-hand electric vehicle power battery ladder, but also amplify the high cost of all-vanadium liquid current batteries drawbacks. According to incomplete statistics, the current cost of all-vanadium liquid current battery is about 3-3.2 yuan / Wh, compared with the average cost of lithium batteries constraints on the development of all-vanadium liquid current batteries is still the factor of high cost, especially the energy storage station can be used in the second-hand electric vehicle power battery ladder, but also amplify the high cost of all-vanadium liquid current batteries drawbacks.only be 1.2-1.5 yuan / Wh, about 40% of all-vanadium liquid current battery. Although the current cost of all-vanadium redox flow batteries is relatively high, compared with the historical trend of lithium battery prices, the cost of all-vanadium redox flow batteries is likely to plummet as the scale expands.

References：

[1]刘涛,葛灵,张一敏.全钒液流电池关键技术进展与发展趋势[J].中国冶金,2023,33(04):1-8+133.DOI:10.13228/j.boyuan.issn1006-9356.20221005

[2]谢聪鑫,郑琼,李先锋等.液流电池技术的最新进展[J].储能科学与技术,2017,6(05):1050-1057.