The quality problem of energy storage and the battery energy storage industry

China Energy Storage Network News:

The lithium battery industry is at a crossroads. Going forward, the energy storage industry will continue to develop healthily and sustainably by strictly and effectively implementing the standards in all aspects; To the left, implementing the standards afterward.

The energy storage industry will be in a dilemma; to the right, implementing the standards beforehand and “releasing water” after the event, there will be many loopholes, and the ant’s hole will break the embankment of a thousand miles.

Fire accidents that occur from time to time push the energy storage, which is at the “wind” of the industry, to the “peak” of public opinion again and again. In this context, battery safety has become one of the bottlenecks facing the development of the energy storage industry.

For the energy storage industry, which has just started its standard application and still has much imperfect product quality and safety, how can it continue to develop?

A few days ago, industry insiders pointed out in an interview with this reporter that my country’s energy storage industry is at a crossroads of development. It is essential to manage all links of the electrochemical energy storage chain, including all components, in a closed loop, to strictly implement national standards, and to develop the industry in a sustainable and healthy way.

Energy storage industry

Energy storage battery quality problems are prominent.

Yibiao, director of the Battery Energy Storage Technology Inspection Department of the China Electric Power Research Institute, recently stated in the online exchange of “Hundreds of Energy Storage Lectures” that in addition to pumped storage, electrochemical energy storage projects account for the largest proportion, which is the development of the energy storage industry. The main direction of attack, among which lithium-ion battery energy storage is the fastest developing electrochemical energy storage technology.

It is impossible to ignore product quality and safety issues in the rapid development of lithium-ion battery energy storage. “At present, the lithium-ion battery energy storage power stations put into operation in my country that has not undergone all-link inspections in accordance with relevant energy storage standards have ambiguous areas in terms of actual usable capacity, energy efficiency, lifespan, safety, and key control parameters. The battery performance indicators are not clear. , lack of effective information, information asymmetry, and even untrue information.”

According to Guan Yibiao, “At this stage, so-called low cost means low cost without quality and safety.”

First of all, the capacity of energy storage batteries fails to meet the standard. The China Electric Power Research Institute often encountered a phenomenon in testing and testing in which the measured values of the battery capacity did not reach the rated values, and this is a common phenomenon in falsely reporting battery capacity.

Secondly, the phenomenon that the life of energy storage batteries does not meet the standard is also common. 

“From the perspective of the actual operating life of the system, the supplier usually promises that the battery capacity retention rate of the system is not less than 80% within 10 years.

In practical applications, the actual operating setting value is much lower than the promised rating, resulting in the objective fact that life under rated conditions is difficult to meet the standard.” When it comes to a battery life test, Guan Yibiao says that the battery that is typically cycled 4,000 times by a power battery test method can only be cycled 2000 times by a standard for energy storage batteries. Life verification is a long-term process, and some third-party test reports that provide 6,000 or even 7,000 lifetimes are unbelievable.

In addition to the above problems, there is also the problem of random changes in key control parameters of energy storage batteries. During the operation of the energy storage system, frequent alarms of battery voltage and temperature often occur, resulting in the protective shutdown of the system.

The supplier does not follow the technical standard requirements and technical agreements of both parties to change key battery control parameters at will, such as power, voltage limit, Temperature limits, etc., and random changes of key control parameters will directly affect the actual usable capacity, safety, and life of the battery system.

In Guan Yibiao’s view, energy storage power stations that have not been strictly inspected by standards have greater potential safety hazards. Combustion accidents have occurred at home and abroad. For example, South Korea mainly uses ternary batteries to build energy storage power stations. 1.7% of the power stations put into operation have experienced combustion accidents, and domestic ternary batteries and lithium iron phosphate battery energy storage power stations have also experienced combustion. ACCIDENT.

In addition, in the test of the battery management system, there are usually cases where the measurement accuracy, electromagnetic compatibility, and resistance to humidity and heat are not up to standard; in the grid-connected test of the energy storage system, there are usually active power regulation capabilities, low voltage ride-through capabilities rated energy and energy. Efficiency and other performance are not up to standard.

Energy storage technical standards are not strictly and effectively implemented.

Since there are many of the above problems, does it mean that the current battery energy storage technology route will not work?

“It’s not that the battery energy storage technology is not good, but that the technical potential has not been correctly guided.” Guan Yibiao believes that battery energy storage has passed the large-scale demonstration application at the national level, passed the functional verification, and the large-scale commercial application has verified that lithium iron phosphate, The feasibility of battery technology routes such as lithium titanate, and the national standard type test results of energy storage batteries show that the performance of mainstream products can fully meet the standard requirements, and the performance of some products far exceeds the national standard requirements. “The root of the problem is that the technical standards for energy storage are not strictly and effectively implemented.”

The technical standards mentioned by Guan Yibiao are not strictly and effectively implemented. The root cause is that users do not have a deep understanding of the technical characteristics of batteries, the supply and demand sides do not fully understand the difference between energy storage batteries and power batteries, and they do not strictly follow the standard requirements in all aspects and transmit them to product design. manufacture.

For example, there are huge differences between energy storage batteries and power batteries in terms of application requirements, test evaluation methods, key technical performance, safety requirements, application of standards, and technical management modes. Electric energy storage applications are more sensitive to safety due to the high safety, long life, and low cost of batteries. In contrast, electric vehicle applications are more secure and reliable due to the high energy density, large-capacity monomer, high rate, and wide temperature range of batteries.

The problem has a limited impact. In terms of thermal runaway safety, the power battery is only at the system level and requires escape time, while the energy storage battery is directly at the battery cell and module body level, requiring no fire and no explosion; due to differences in user subjects, the application management of electric vehicle power batteries It presents decentralized and divergent management, while the application management of power storage batteries belongs to centralized convergent management.

The application management experience in the power battery industry does not apply to the energy storage industry. For a long time, the supervision of battery energy storage equipment has not been strictly and effectively implemented. The energy standard has not been achieved, and the closed-loop management of all links before, during, and after the event has not been realized, which brings huge hidden dangers to the safe, reliable, efficient, and stable operation of the battery energy storage power station.

Another reason why the standards are not strictly and effectively implemented is that users and related parties have an incomplete understanding of the energy storage technical standards, one-sided emphasis on certain aspects of the indicators, taking the standards out of context, avoiding the important ones, and failing to fully consider and pay attention to the various parameters and various aspects of the standards. Correlation and complexity between item properties.

Setting the Safety Bottom Line for the Operation of Energy Storage Power Stations

To solve the safety risk of energy storage batteries, the main method at present is to actively reduce the capacity and reduce the parameters. Although this can delay safety accidents and capacity decay to a certain extent, it sacrifices the actual available capacity and user rights and interests. So, how do we effectively solve the pain points of energy storage battery applications?

Guan Yibiao proposed strengthening the detection and evaluation of the thermal characteristics of battery cells and battery modules and setting a bottom safety line for the safe operation of energy storage power stations from the root cause. For example, the safety test rejects by one vote, which fundamentally sets a safety entry threshold for the large-scale application of energy storage batteries.

“There is no limit to the technical type and technical characteristics of the battery, and the battery technology system with any charging and discharging time can compete on the same stage. On the announcement of meeting the requirements of technical standards and the boundary conditions of the user’s site, the competition will finally be based on the economy.” Guan Yi The standard believes that the battery energy storage standard sets the progressive product levels of battery cells, battery modules, battery families, and battery systems, and testing and evaluating them respectively are relatively independent and complementary to each other, forming an organic whole, which is convenient for All relevant parties fully obtain information to ensure that the key control parameters and performance of each product level are effectively transmitted step by step, and conform to the correct logical relationship, and the information presented to users is sufficient, effective, clear, and opportunistic.

In addition, due to the particularity of the battery, the evaluation of its quality depends heavily on unified test conditions and systematic, measured data. Therefore, only by implementing full-link technical management can the effective control of battery quality and safety be achieved. In addition to incorporating the type test report and performance evaluation certificate as the basis for technical evaluation into the unified requirements for prior supervision of energy storage equipment procurement, the battery arrival sampling inspection further incorporates system grid connection inspection into the in-process supervision process.

The actual charging includes during the system operation process. The operation assessment and testing of discharge energy includes energy efficiency in the post-event supervision process. The entire chain and all links of the energy storage equipment involved in the power grid operation, the power supply side, and the user side are closed-loop management. The quality and safety professionally conduct the battery energy storage equipment. Authoritative, comprehensive technical supervision and inspection can ensure that the energy storage equipment connected to the grid can safely and reliably perform its established functions and performance. It can also guide the energy storage industry to move towards a standardized, healthy, and sustainable development that strictly implements energy storage standards. In terms of the energy industry, it is possible to fundamentally reverse the development trend of “bad money drives out good money”.

After the energy storage connects to the power grid, it becomes an important main body of the power grid operation.No matter who is the main body of the energy storage investment and operation, the power grid actually assumes the responsibility for the grid connection of the energy storage equipment. Suppose a set of mandatory quality and not form safety requirements in advance of Technical supervision and management requirements. In that case, access to a large number of low-cost and low-quality energy storage equipment will bring huge potential hidden dangers to the safe production and operation of the power grid.


Guan Yibiao said bluntly: “The battery energy storage industry is at a crossroads. Going forward, the energy storage industry will develop healthily. By strictly and effectively implementing the standards in all aspects, the energy storage industry will continue to show low prices and prices. The vicious development situation of quality and smearing; to the left, the implementation of the standards after the event, the energy storage industry will be in a dilemma; to the right, to implement the standards in advance and ‘release water’ after the event, there are many loopholes. The ant’s nest will collapse for thousands of miles.embankment.”

Source: China Energy News