Analysis and prospects of new energy storage technology routes

Electricity storage can be divided into three categories: electrochemical energy storage, mechanical energy storage and electromagnetic energy storage.

Electrochemical energy storage mainly includes lithium-ion batteries, flow batteries, lead batteries and sodium-ion batteries; mechanical energy storage mainly includes compressed air energy storage, flywheel energy storage and gravity energy storage; electromagnetic energy storage mainly includes supercapacitor energy storage and superconducting energy storage, etc.

Electrochemical energy storage is the most widely used new energy storage technology and has the potential for large-scale promotion. Electrochemical energy storage is a technology that stores electrical energy through electrochemical reactions.

Compared with other energy storage technology routes, electrochemical energy storage systems have higher energy density, moderate response speed, wide application range, easier mass production, installation, operation and maintenance, and excellent potential for large-scale promotion.

Of the global cumulative installed capacity of new energy storage in 2022, 97% will be electrochemical energy storage (of which lithium-ion batteries account for 94.4%). As the industrial chain matures, technology advances and costs decline, the prospects for electrochemical energy storage become broader.

• Lithium-ion battery energy storage

1. Technical features: Lithium-ion batteries have the advantages of fast charge and discharge speed, high overall efficiency, strong technical practicality, and few limiting factors. Among various electrochemical energy storage technologies, lithium battery energy storage has outstanding performance in terms of cycle times, energy density, response speed, etc. All have great advantages. However, lithium-ion batteries have shortcomings such as safety and poor low-temperature performance.
2. Application scenarios: Lithium-ion batteries have a wide range of application scenarios and can be used in all aspects of the power supply side, grid side, and user side of the power system, including AGC frequency modulation power stations, wind/solar energy storage power stations, peaking/frequency modulation power stations, emergency power supplies, etc.; the application modes are diverse and can Achieve multiple functions such as peak shaving and frequency modulation.
3. Technology maturity: At present, lithium-ion battery technology has achieved large-scale application, with lithium iron phosphate battery technology as the main technology route. Judging from the current commercialization process, lithium-ion battery technology is very mature. In the future, we will focus on research on safety materials, intelligent manufacturing, and battery recycling and reuse.

• Flow battery energy storage

1. Technical features: Flow cell batteryhave the advantages of safety, reliability, high cost performance during the life cycle, environmental friendliness, and long cycle life. The water-based electrolyte characteristics of the flow battery can prevent it from burning and exploding, and it is highly safe; the power and capacity of the battery are independent of each other, realizing the separation of the power and capacity of the stack, and the capacity can be expanded by increasing the capacity of the liquid storage tank ;Also has long cycle life. However, flow batteries have shortcomings such as low energy density and high cost.
2. Application scenarios:On the one hand, the service life of the flow battery is consistent with that of wind and photovoltaic power stations, so it is suitable for the construction of large-scale new energy power stations for distribution and storage; on the other hand, due to the large scale, large capacity, long life, high residual value, and The maintenance cost is low, so it can be used in large-scale shared energy storage power stations or peaking power stations on the grid side.
3. Technology maturity: China’s flow battery energy storage technology has reached the international leading level, and large-scale all-vanadium flow battery energy storage technology has initially achieved industrialization. However, it still needs to further improve the performance of large-scale energy storage systems, reduce system costs, and develop different The operating mode of the application scenario.

• Lead-acid battery energy storage

Technical features. Lead-acid batteries have the advantages of low cost, good high-rate discharge performance, and good temperature performance. However, lead-acid batteries have shortcomings such as low energy density.

1. Application scenarios: Lead-acid battery energy storage technology has outstanding advantages such as low cost and high safety. It can be widely used in various new energy energy storage systems such as solar energy, wind energy, wind and solar hybrid, smart grids, microgrid systems, and power supply in areas without mains power and harsh power grids.Energy storage systems, power frequency regulation and load tracking systems, power peak-shaving and valley-filling systems, and residential area energy storage and charging systems, etc.
2. Technology maturity:Lead-acid batteries are the most mature technology route in electrochemical energy storage. Judging from the current commercialization process, lead-carbon battery technology is currently the main technology route and is in the middle and late stages of commercialization.

• Sodium-ion battery energy storage

1. Technical features: As a new type of secondary chemical power source, sodium-ion batteries not only have no resource constraints in raw materials, but also have safety, high and low temperature performance, and high-rate charge and discharge performance, with obvious resource and cost advantages. However, sodium-ion batteries have shortcomings such as low energy density and short cycle life.
2. Application scenarios. Sodium-ion batteries can be used in load frequency regulation, grid peak shaving and valley filling, renewable energy grid integration, and improvement of power quality.On the power generation side, sodium-ion battery energy storage systems can cooperate with thermal power units to take advantage of their fast response speed and strong instantaneous power regulation capabilities to provide frequency and voltage regulation services.Under automatic generation control (AGC) system scheduling, sodium-ion battery energy storage systems can cooperate with new energy systems such as wind power and photovoltaics to improve the power system’s regulation capabilities and reduce wind and light abandonment rates.
3. Technology maturity: Domestic work in the research and development, manufacturing, standard setting, market promotion and application of sodium-ion battery products is in full swing, and sodium-ion batteries are about to enter the commercial application stage.

• Other cutting-edge electrochemical energy storage technologies

There are many electrochemical energy storage technology routes, and research and development of various cutting-edge new energy storage technologies are currently being carried out at home and abroad, focusing on overcoming the shortcomings of existing electrochemical energy storage technologies from the perspective of low cost, high safety, and large scale.

Based on the electrochemical energy storage technology system, among the many cutting-edge battery mechanisms and technical solutions, the more representative ones include solid-state batteries, aqueous batteries, multi-electron secondary batteries (magnesium-ion batteries, aluminum-ion batteries, etc.), metal-air batteries and Liquid metal batteries are currently in the exploration and research and development stages.