Recently, Academician Zhao Tianshou of the Chinese Academy of Sciences and Dean of the Institute for Carbon Neutrality and Energy at Southern University of Science and Technology, gave a keynote speech titled "New Type of Flow Battery Energy Storage Technology" at the Carbon Neutrality Energy Summit. The content was divided into four aspects:

1. Why develop long-term energy storage technology: solar and wind power generation face challenges, and energy storage technology development is key：

Academician Zhao Tianshou stated that although China has achieved good results in solar and wind power generation technology, from the perspective of China's energy structure, the proportion of solar and wind energy is 5%. To truly achieve "carbon neutrality" by 2060, the proportion of solar and wind energy needs to reach more than 60%. Overall, the challenge is great; Due to the uncertainty and intermittency of solar and wind energy, further expansion of their utilization scale faces challenges, and the most effective way to address the shortcomings of solar and wind energy is to develop energy storage technology.

The energy storage technology to be developed should meet the following requirements: firstly, safety and reliability, safety is the most basic requirement for energy storage systems; The second is economically feasible, only economically feasible technologies can be accepted by society; Thirdly, resources should be accessible, and the technological requirements for resources should be met. Installation should not overly rely on natural conditions or geographical environments.

2. The application and role of long-term energy storage technology on the generation side, grid side, and user side：

Zhao Tianshou further pointed out that long-term energy storage technology is an important development direction in the field of energy storage, which can play a huge role in the generation side, grid side, and user side.On the power generation side, long-term energy storage is mainly used for grid connection and can avoid power interruption, especially when wind and solar power dominate. The ideal energy storage duration should cover the wind and solar intermission period, exceeding 10 hours;

On the power grid side, in order to promote the long-distance transmission of wind and solar power, China has built multiple cross regional power grid lines. Due to the fluctuation of power generation and the mismatch between supply and demand, cross regional transmission may encounter power troughs, such as a 6-hour trough period; Therefore, it is necessary to have energy storage technology that exceeds the duration of the off peak period to achieve peak shaving and valley filling of electricity, thereby improving the utilization rate and transmission capacity of the power grid;

On the user side, the main advantage of long-term energy storage technology is to reduce electricity costs. For industrial and commercial users, electricity prices can usually last for more than 6 hours during off peak periods, and the same applies during peak periods. In order to reduce electricity costs, industrial and commercial users need to equip energy storage systems that can last for more than 6 hours to store electricity at low valley prices and use it during peak hours, effectively reducing overall electricity costs.

3. Regarding how to use electrochemical energy storage technology to achieve long-term goals：there must be a flowable energy carrier and corresponding energy conversion devices

Academician Zhao Tianshou conducted a comparative analysis of technologies such as pumped storage, compressed air storage, and lithium battery storage. Pumped storage technology uses water as the energy carrier, and due to the fluid characteristics of water, there is a decoupling phenomenon between energy and equipment. However, the implementation of this technology is strictly limited by geographical conditions, especially the influence of climate factors; As for compressed air energy storage technology, its energy carrier is air, which, as a fluid, has flexibility in terms of time and a longer service life. However, compared to pumped storage, its efficiency is slightly lower and there are certain challenges in site selection, requiring sufficient storage space; Lithium ion battery technology exhibits many advantages, including high energy density and high energy conversion efficiency, as well as flexible site selection conditions. However, its main limitation is that the active material of the energy carrier cannot flow, resulting in a close relationship between capacity and power. If the usage time is to be extended, it may be constrained by various factors such as cost, safety, and performance.

In summary, Dean Zhao Tianshou introduced that flowable energy carriers and corresponding batteries, including electrolytes, fuel cells, flow batteries, etc., are collectively referred to as fluid batteries. The biggest feature of fluid batteries as energy storage systems is their flexible duration, scale, and capacity expansion. At the same time, the site selection is relatively simple, making them an ideal long-term energy storage technology. As a type of fluid battery, the new flow battery is inherently safe, flexible in duration, has a long cycle life, and has a high residual value for recycling. It is one of the most widely used and promising long-term energy storage technologies.

4. The development potential of flow batteries is great： improving current density and electrolyte utilization is the key to cost reduction

In recent years, China has attached great importance to the development of flow batteries, among which all vanadium flow batteries are currently the most widely promoted and applied. However, cost is the bottleneck that this technological route must overcome. Therefore, Academician Zhao Tianshou stated that the increase in current density is accompanied by an increase in power density, which means a decrease in the amount of construction materials used, thereby reducing the initial installation cost; In addition, the improvement of electrolyte utilization can reduce the amount of electrolyte used and also lower the cost of the battery.

In the flow battery industry, ZH Energy Storage has been at the forefront of solving major material cost reduction challenges in the long-term energy storage market, relying on the nearly 20 years of experience accumulated by co-founder Dr. Xie Wei in the US flow battery industry to address current density and electrolyte utilization issues. The company effectively solves the current market pain points and resource problems by developing low-cost and high-performance revolutionary key materials, improving the power density of the fuel cell stack, developing high-performance and low-cost PBI ion exchange membranes, and developing resource rich and low-cost sulfur iron electrolytes, in order to reduce the installation cost and lifetime electricity cost of flow batteries, making them a competitive advantage for long-term, low-cost, and safer large-scale energy storage technologies.