In September, China's market in vanadium battery companies ushered in two landmark events. On September 20, the Three Gorges Energy Xinjiang 250MW/1GWh all-vanadium liquid flow energy storage project started. It is reported that this is the first GWh-class all-vanadium flow battery project in China and will be connected to the grid by the end of 2023.
On September 29, the first national-level large-scale chemical energy storage demonstration project, the world's largest all-vanadium flow battery energy storage power station, and the first phase of the Dalian flow battery energy storage peak-shaving power station project have been integrated into the Liaoning power grid. It is expected to be put into use in mid-October. Compared with vanadium battery vs lithium in energy storage, vanadium battery seems to be becoming the new darling of the energy storage track, which brings up a question, vanadium battery vs lithium, will vanadium battery be the future?
1. The advantages of vanadium battery are obvious
● The first advantage of vanadium batteries is high safety.
Since the electrolyte matrix of the vanadium battery adopts an aqueous solution, there is no solid-phase reaction during use, so there is no risk of fire and explosion. Moreover, overcharging and overdischarging will only cause the electrolysis of water, and safe use can be guaranteed by discharging the generated hydrogen in time. Usually, the electrolyte and the stack are stored separately, which also successfully avoids the self-discharge phenomenon.
● The second advantage of vanadium batteries is the simplicity of capacity expansion.
Vanadium batteries can be easily applied in modular management, and power and capacity can be individually designed. By connecting multiple groups of energy storage units in parallel to the bus, a larger-scale energy storage system can be built. Therefore, the capacity expansion is simple, and compared with lithium iron phosphate batteries, no additional safety risks will be added in the case of large capacity.
● The third advantage of vanadium batteries is long cycle life.
Vanadium batteries do not undergo physical changes during use, and the battery capacity loss is small. Even if the battery has been used for too long and its performance has deteriorated, it can be recovered by repairing the activity of the electrolyte. Compared vanadium batteries vs lithium, vanadium batteries, the service life is often more than 10 years, and it can be charged and discharged more than 15,000 times, which is more than three times that of lithium batteries. In the Dalian energy storage power station mentioned at the beginning, the vanadium battery can be charged and discharged more than 20,000 times.
● The fourth advantage of vanadium batteries is the lower cost of the whole cycle life.
The initial investment cost of vanadium batteries is high, but due to the long cycle life of vanadium batteries, they have certain advantages in terms of full life cycle costs.
2. Disadvantages of vanadium battery
The low energy density of vanadium batteries is a major disadvantage. Comparison vanadium battery vs lithium, due to the relatively large molecular mass of vanadium, the energy density of vanadium battery is only 12-40Wh/kg, which is only one tenth of that of lithium battery. However, the volume is 3-5 times that of lithium batteries, which greatly hinders the application of vanadium batteries in consumer electronics and power batteries. Second, the initial installation cost of vanadium batteries is too high.
Comparison vanadium battery vs lithium, due to the imperfection of vanadium battery industry chain, its current initial installation cost is more than twice that of lithium battery, and it may not reach the level lower than lithium battery until mass production. At the same time, vanadium batteries have nearly harsh requirements on ambient temperature.
The maximum temperature cannot exceed 45°C, because once this temperature is exceeded, precipitates will precipitate in the positive electrode solution to block the flow channel and make it scrapped. However, for batteries, the electrolyte is exothermic as long as it is reacting, and 45°C is a very easy temperature to reach.
3. Vanadium battery vs lithium batteryThe difference between vanadium battery vs lithium battery is mainly reflected in the following aspects:
① Battery structure
The electrolyte and stack of vanadium batteries are independent of each other, so the design of vanadium batteries is flexible and can be combined and customized as needed. However, vanadium batteries are much larger than lithium batteries. The power unit and capacity unit of vanadium battery are independent decoupling design, which has strong capacity expansion and modular design, which is more conducive to realizing large-scale and low-cost long-term energy storage.
The output power of vanadium redox flow battery is determined by the number and size of the battery stack, and the energy storage capacity mainly depends on the volume and concentration of the electrolyte, and the capacity can be adjusted arbitrarily according to the demand. The capacity growth of lithium batteries is non-linear, and the marginal cost of capacity expansion is high.
Since lithium batteries use highly flammable organic electrolytes, there is a risk of deflagration in the event of thermal runaway, which can only be reduced but cannot be absolutely avoided. According to relevant statistics, from 2011 to April 2022, a total of 34 energy storage power station explosions occurred around the world, of which 32 were caused by lithium batteries.
In addition, our website organizes related energy storage lithium battery companies in China, which will help you to learn more about batteries used in energy storage. Comparison vanadium battery vs lithium, All-vanadium redox flow battery is a water circulation system, which is non-flammable and does not generate heat accumulation. The positive and negative active materials react mildly, so it is inherently safe.
③ Amount of mineral resources occupation
Vanadium resources are independently controllable. As of the end of 2021, China's vanadium reserves account for 39% of the world's reserves and 68% of the world's production, ranking first in the world. China's lithium reserves account for only 7%, and the resources are concentrated in Chile (41%), Australia (25%), and Argentina (10%).
In the short term, the initial investment cost of lithium-ion batteries is lower than that of all-vanadium flow batteries, mainly due to the lack of scale effects of all-vanadium flow batteries. However, in the long run, the average cost of all-vanadium redox flow batteries in the whole cycle life is much lower than that of lithium-ion batteries, and there is still a large room for the initial investment cost to decrease. At present, the installed capacity of lithium batteries accounts for 90% in China.
However, in the scenario of large-scale and large-capacity energy storage demand in vanadium battery vs lithium, vanadium batteries are gaining momentum. It is expected that the installed capacity of long-term energy storage will reach 150GW in 2030, and the cumulative increase of vanadium batteries in China is 24GW. The increasingly hot market and potential growth space seem to be gradually proving that vanadium batteries may really be expected to lead the future of energy storage.