In high-power application scenarios such as electric vehicles (EV), Energy Storage Systems (ESS) and industrial robots, the wide application of batteries continues to promote the innovative development in the field of battery management monitoring and control. The next generation battery management system (BMS) is responsible for extending battery life, ensuring ultra-high reliability, and providing ultra-high safety for users and passengers. However, in recent years, accidents such as battery failure recall, over-use of cell and fire and property loss caused by rapid failure of battery pack have occurred frequently, which has seriously damaged the reputation of many battery suppliers and OEM. Therefore, industry and government regulatory agencies have promoted the detection method and safety to the top priority of the next generation of battery products.
In order to effectively cope with these safety and reliability challenges, designers have focused on electrochemical impedance spectroscopy (EIS) technology. This technology has been applied in the battery field for decades. EIS is a method to gain insight into the battery condition and status by stimulating the battery cell and monitoring its response. In this process, designers can use non-invasive electrical signals to monitor multiple key aspects of battery cell, accurately obtain battery temperature, battery power (state of charge), important information such as battery attenuation (health status) and thermal runaway detection. This article will deeply analyze the current challenges faced by battery system designers, and elaborate on how EIS can help realize more reliable and longer life battery design.
Introduction
in the past ten years, the electric vehicle industry has achieved rapid development. This change cannot be separated from major engineering breakthroughs, which have successfully overcome the limitations of early endurance, charging speed and battery reliability. Although some skeptics are still worried about battery life anxiety and battery capacity decay over time, many breakthroughs have effectively solved these problems. For example, through the continuous innovation of cell chemical composition and manufacturing process, the battery energy density has been greatly increased from 100Wh/kg to 300Wh/kg; The improved charging infrastructure has significantly accelerated the charging speed, the charging time can be shortened from more than eight hours to less than 30 minutes to complete 80% of the charging; The advanced high-voltage application specific semiconductor is adopted to realize more battery monitoring, it can effectively manage cell with more than 200 battery pack connected in series in 400V and 800V architectures.
Even with the above remarkable progress, battery system designers still face three major challenges. The first is life cycle management. Designers must improve the reliability and service life of high energy density lithium batteries (such as lithium iron phosphate [LFP] and nickel manganese cobalt [NMC] ternary lithium). These cell are extremely sensitive to factors such as temperature fluctuation, overcharging, undercharging and high charging rate, and need to be monitored and controlled.Find a delicate balance between systems to ensure the reliability and stability of the battery. The second is aging and capacity attenuation. Currently, cell capacity attenuation can only be predicted by models and cannot be measured directly, which brings great difficulties to accurate prediction. Consumers can also clearly feel this problem when using new smart phones. The fully charged battery can last for several days at initial stage of using, but with the aging of the battery, its capacity gradually decreases, in the end, it may only be a fraction of the original capacity., Safety and thermal runaway are urgent challenges facing the industry. Driven by both industry pressure and government regulations, it is imperative to detect cell stress and damage that trigger catastrophic thermal runaway.
In order to meet these challenges, it is imperative to adopt new tools, and EIS technology is one of the promising ones. It allows designers to gain real-time insight into the status and condition of the battery, as if they have a pair of "see-through eyes" to effectively observe the actual situation inside the cell.
Use EIS to analyze batteries
what has changed? Regulations promote earlier detection
thermal runaway refers to the chain reaction in which the cell starts self-heating, supercharging and finally burns. Once this reaction occurs, it will spread to other cell quickly, causing the whole battery pack to catch fire, and this process can hardly be stopped and can only be contained. Therefore, the battery industry and government regulators are actively taking measures to achieve earlier thermal runaway detection and strive for a longer warning time for drivers. In 2020, China's national standard (GB)38031 national standard stipulates that at least five minutes of escape time must be ensured after a thermal runaway warning is issued. The revised version of GB 38031-2025, which will take effect in July 2026, further extends the window period to at least two hours, that is, the time before the external open flame or explosion occurs after a single cell enters the state of thermal runaway battery pack.
These strict standards put great pressure on automobile manufacturers, requiring them to implement thermal runaway detection at a single cell level and strive for every minute of warning time as much as possible. Unfortunately, there are few effective solutions to ensure that this requirement is met. EIS technology provides a new way to solve this problem. It can integrate measurable electrical the rate of pillow inner insights into the next generation of BMS devices of Texas Instruments (TI).
What is EIS?

Spectrum analysis is a technology widely used in many fields, which detects the characteristics of the system by stimulating and measuring the response of the system in the whole frequency range. For example, in biological spectrum analysis, intelligent scales send different frequencies to the human body.Rate current signal to measure muscle, fat and moisture content to estimate body composition. The electrochemical part of EIS skillfully applies this principle to the battery field and uses electrical signals to measure the chemical reaction of the battery.