Star Energy 3.2V 155Ah Storage Type LifePo4 Battery Cell has a cycle life of more than 6000 times

Speech by PH.D Lou Zhongliang, executive vice president of Star Energy Research Institute, at the annual meeting of lithium battery & electric vehicle of senior engineering

On December 18, Lou Zhongliang, executive vice president of the Star Energy Institute, delivered a keynote speech on "ultra long cycle life solutions and development progress" at the 2020 high tech lithium & electric vehicle annual conference.

PH.D Lou Zhongliang from energy storage background, analysis of influencing factors of cycle life decline, decline analysis and model of conventional LFP energy storage system, ultra long cycle life solution and current development of ultra long cycle life products of Star Energy.

The progress is described in detail.

Using energy storage technology to realize the coordinated operation of source network load storage

PH.D Lou Zhongliang extended into China based on the current situation of energy storage in recent years. From the change of energy structure, in 2018, the total amount of wind power generation in China was 543.5 billion kwh, accounting for 7.8% of the full caliber power generation. Wind power generation continues to grow

Rising, thermal power continues to decline; In this year, wind power and photovoltaic power generation accounted for more than 20% of the total power generation in 9 countries around the world. For example, Denmark 51%, Uruguay 36%, Germany 26%, Portugal 24%

Britain 21%. In the first half of 2019, the proportion of wind power and photovoltaic power has exceeded 50%.

Starting from the characteristics of wind and solar power generation, wind and solar resources have typical intermittent and unstable characteristics, which do not match the power consumption side. The direct connection of large-scale wind and solar power generation to the power grid will affect the whole power system, including production

Transmission to all links of consumption brings challenges to the safe and stable operation of power system, making it difficult to predict, control and dispatch. From the perspective of supply, transmission, distribution and utilization, it is urgent to make use of energy storage technology

The coordinated operation of source, network, load and storage is realized in milliseconds, seconds, minutes, hours and multi time scales.

Electrochemical energy storage will become the mainstream technology in this field

PH.D Lou Zhongliang analyzed the types and characteristics of energy storage technologies. He said that according to different types of technologies, the energy storage methods released by electric energy are mainly divided into mechanical energy storage, electromagnetic energy storage and electrochemical energy storage

Energy technology has different internal characteristics. Taking pumped storage (PHS) as an example, it is the most deployed energy storage mode so far, accounting for 94.11%, but its comprehensive efficiency is too low and is not suitable for frequency modulation and frequent start and stop

Therefore, electrochemical energy storage will become the mainstream technology in this field due to the comprehensive response time, comprehensive efficiency, service life, technology maturity and scenario applicability.

According to the proportion of electrochemical energy storage installed capacity in recent years, according to cnesa data, among the energy storage projects put into operation in the world in recent five years, the proportion of lithium-ion battery energy storage system has exceeded 80%, becoming the mainstream electrochemical energy storage technology

Surgical route.

LFP energy storage system decline, Star Energy solution strategy

PH.D Lou Zhongliang stressed that energy storage has extremely strict requirements on the safety, life cycle cost and integration of lithium-ion batteries, which requires lithium battery enterprises to further improve product performance as the key index.

Although LFP battery has attracted more and more attention in the energy storage market because of its advantages in safety and cycle life, there is also an obvious problem of decline.

PH.D Lou Zhongliang analyzed the decline of LFP energy storage system. First, the loss of active lithium accounted for 59% of the total capacity loss; Second, the polarization loss accounts for 17% of the total capacity loss; Third, the loss of active substances accounted for 24% of the total capacity loss. in the light of

For this series of reasons, the solution strategy of Star Energy technology is to reduce the consumption rate of active lithium (i.e. reduce the expansion of graphite, adjust solvents and additives to form high-quality SEI, reduce the impact of impurities on SEI (FE dissolution)), and increase

Add the total amount of available active lithium (lithium supplement and artistic SEI) and inhibit the lithium precipitation caused by polarization growth (i.e. adjust the compaction density of negative electrode and the area density).

The specific solution is to develop the electrolyte independently and improve the additives, solvents and lithium salts; Customized development of positive and negative electrodes; In the production of pole piece, it is improved to select high strength and high elastic viscosity

The binder inhibits the apparent expansion of the polar long cycle process and constructs a high-quality conductive network: conductive carbon black + carbon nanotubes.

PH.D Lou Zhongliang said that at present, the 155ah long-life lithium iron phosphate energy storage battery produced by Star Energy has been widely used in large-scale energy storage power stations, with a cycle life of more than 6000 times, and has passed IEC 62619:2017 

Ul1973, GB / T 36276-2018, JIS C 8715-2:2019, UN38.3 and China Classification Society.

Meanwhile, Star Energy is also developing a long-life lithium iron phosphate energy storage battery with a cycle life of more than 10000 times to further explore and explore the technical potential and application space of LFP battery.