Average cycle life of ordinary lithium iron phosphate batteries

Walking into the National Wind-Light Storage and Transmission Demonstration Power Station in Zhangbei County, you can see rows of towering white wind turbines and sparkling blue photovoltaic panels on the green grassland.

This is the largest wind and solar storage and transmission demonstration project in my country. It adopts the world’s first wind and solar storage and transmission combined power generation construction ideas and technical routes. It is a comprehensive new energy demonstration project integrating wind power, photovoltaics, energy storage devices and intelligent power transmission. .

This power station can “store” wind and light resources that are “difficult to predict, control, and dispatch”, and convert them into high-quality and reliable green power for input into the grid, and can operate in “smooth fluctuations” and “peak shaving and valley filling”. Flexible switching between modes, in the case of loss of external power supply, the energy storage power station can maintain the normal operation of the power grid through the internal self-starting capability.Also read:Residential Storage Batteries

The development of energy storage technology is one of the key core technologies to promote new energy power generation and improve the security and stability of the power grid. Among various types of electrochemical energy storage technologies, lithium titanate batteries have the characteristics of long cycle life and good safety performance, which are well suited to the application scenarios of grid energy storage, but the high cost of lithium titanate batteries is not conducive to Large-scale energy storage applications.

In this regard, China Electric Power Research Institute, together with a number of units, jointly established a project team of “development of low-cost lithium titanate batteries for energy storage and development and application of system integration technology”. After years of research, the project team has put forward the material system and production process reconstruction principles and technical solutions for the lithium titanate battery based on the original lithium titanate battery based on the needs of energy storage applications, and developed a sub-micron scale Lithium titanate material. The lithium titanate battery for energy storage developed by the project maintains the intrinsic characteristics of long life, while the cost is greatly reduced. In the 2017 Beijing Science and Technology Awards, the project won the second prize.

The next outlet for new energy

Energy storage is considered to be the next outlet for new energy. As a forward-looking technology to promote the development of the new energy industry in the future, the energy storage industry will play a huge role in new energy grid integration, new energy vehicles, smart grids, microgrids, distributed energy systems, and home energy storage systems.Also read:10kwh 48V Lifepo4 Manufacturer

“The reason for the development of energy storage is that photovoltaic and wind power generation are intermittent and unstable, so the cooperation of the energy storage system is required to provide stable and reliable power.” Director of the Energy Storage Battery Ontology Research Office of the China Electric Power Research Institute Yang Kai told reporters.

The use of large-scale energy storage technology can promote the development of renewable energy, improve the security and stability of the power grid, improve the quality of power supply, and effectively alleviate the contradiction between power supply and demand.

Large-scale energy storage systems run through all aspects of power generation, transmission, distribution, and use. Its application can not only improve the performance of traditional power systems, but also revolutionize the planning, design, layout, operation management, and use of power grids. In this sense, energy storage technology is a technical commanding height of national strategic significance, and the development of energy storage technology is actually “storing the future”.

A “wonderful flower” in a lithium-ion battery

It is understood that energy storage technologies are mainly divided into mechanical energy storage, electrochemical energy storage, electromagnetic energy storage and phase change energy storage. In recent years, electrochemical energy storage technology represented by lithium-ion batteries has the characteristics of large energy scale, flexible location selection, and fast response speed, which meets the technical requirements of power systems and the development trend of smart grids. Become the fastest growing power system energy storage technology. Lithium-ion battery is a kind of “rocking chair battery”, and the positive and negative electrodes are composed of two compounds or elements that can de-intercalate lithium many times. During charging, the positive electrode material is delithiated, lithium ions enter the electrolyte and pass through the separator to be embedded in the negative electrode, the positive electrode undergoes an oxidation reaction, and the opposite occurs during discharge.

Lithium-ion battery technology has been in a state of rapid development with the research on battery electrode materials. At present, it has expanded from lithium cobalt oxide batteries to ternary, lithium manganate, lithium iron phosphate, lithium titanate and other battery systems coexisting. The new lithium-ion battery with lithium titanate as the negative electrode breaks through the inherent limitation of graphite as the negative electrode, and its performance is significantly better than that of the traditional lithium-ion battery, making it one of the most promising energy storage batteries. To this end, Yang Kai introduced the four major advantages of lithium titanate batteries to the reporter:

Good security and stability. Due to the high lithium intercalation potential of the lithium titanate negative electrode material, the formation and precipitation of metallic lithium are avoided during the charging process, and because its equilibrium potential is higher than the reduction potential of most electrolyte solvents, it does not react with the electrolyte and does not form solid – The liquid interface passivation film avoids the occurrence of many side reactions, thus greatly improving the safety. “The energy storage power station is the same as the electric vehicle, and safety and stability are the most important indicators.” Yang Kai said.Also read:Custom 48V 800Ah Lithium Battery

Excellent fast charging performance. Too long charging time has always been an insurmountable obstacle in the development of electric vehicles. Generally, pure electric buses with slow charging are used, and the charging time is at least 4 hours, and the charging time of many pure electric passenger cars is as long as 8 hours. The lithium titanate battery can be fully charged in about ten minutes, which is a qualitative leap compared with the traditional battery.

Long cycle life. Compared with graphite materials commonly used in traditional lithium-ion batteries, lithium titanate materials hardly shrink or expand in the skeleton structure during the charging and discharging process of intercalation and delithiation. / The problem of damage to the electrode structure caused by the volume strain of the unit cell when inserting lithium ions, so it has very excellent cycle performance. According to experimental data, the average cycle life of ordinary lithium iron phosphate batteries is 4000-6000 times, while the cycle life of lithium titanate batteries can reach more than 25,000 times.

Good resistance to wide temperature. Generally, electric vehicles will have problems when charging and discharging at -10 °C. Lithium titanate batteries have good wide temperature resistance and strong durability, and can be charged and discharged normally at -40 °C to 70 °C. Whether it is in the frozen Northland, Even in the hot south, the vehicle will not be affected by the “shock” of the battery, which eliminates the user’s worries.

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