Stationary batteries are essential building blocks in critical applications such as backup systems in hospitals, data centers, power substations and renewable energy storage. However, their long-term performance can be compromised by two key threats: component corrosion and thermal safety risks.
Corrosion can affect everything from internal plates to terminals, reducing efficiency and causing premature failure. On the other hand, overheating and thermal leakage pose risks of fire or explosion, especially in stationary lithium-ion batteries. This article offers a comprehensive look at the mechanisms that cause these phenomena and the scientific and technological innovations that can mitigate them.
What is a stationary battery, and how does it work?
Stationary batteries are designed to supply a constant current over an extended period of time and withstand deep discharge cycles without compromising their service life. These batteries can be almost completely discharged repeatedly, making them ideal for backup or continuous power supply applications.
These batteries use thicker lead plates, allowing a greater number of charge and discharge cycles. Their robust construction makes them especially suitable for applications where reliability and energy durability are required. They are used in telecommunications systems, photovoltaic and wind power plants, public and private lighting, data centers, backup systems (nobreaks), remote monitoring, electronic security, ATMs, and telephone exchanges. They provide a constant and secure power supply in environments where operational continuity is essential.
Operating mode and performance
Stationary batteries are equipped with filters that allow the release of hydrogen, but block acid vapors, making it possible to use them in environments shared with people, provided that there is adequate minimum ventilation. The electrodes are made of lead with a purity grade of more than 95%, which contributes to greater electrochemical stability.
They can be discharged up to 80% without damaging their performance or shortening their service life. In addition, they need to maintain an ideal operating temperature of 25 °C, so they are commonly installed in air-conditioned rooms or integrated into air-conditioning systems.
Types of stationary batteries and their vulnerabilities
Stationary batteries come in different technologies that offer particular characteristics in terms of performance, durability, maintenance and associated risks. The most common types and their respective operational and environmental vulnerabilities are detailed below:
- Lead-acid batteries: The most important models include VRLA (Valve Regulated Lead Acid), AGM (Absorbent Glass Mat) and Gel types. These batteries, common in industrial applications, are vulnerable to sulfation and grid corrosion, which weaken the internal structure. The accumulation of hydrogen gas, if not properly vented, can increase the internal temperature. In the following image figure 1, the models of this type of battery are shown.
- Lithium-ion batteries: They have high energy density, higher charging efficiency and longer life cycles. They are preferred in modern applications such as solar storage, telecommunications, and data centers. However, they present considerable thermal risks, such as thermal runaway, formation of metallic dendrites that perforate the internal separator, electrolyte degradation at high temperatures, these events can trigger uncontrolled exothermic reactions.
- Sodium-sulfur and redox flow batteries: These represent the new technologies of solid-state and sodium-sulfur batteries, presenting alternatives with lower risk of internal corrosion and better thermal stability, although their large-scale implementation is still under development.
Corrosion mechanisms in cells and components
Electrochemical corrosion occurs in terminals, plates, connectors, and power distribution systems. Conditions such as high humidity, saline atmospheres or acid gases aggravate metal oxidation1.
- Internal corrosion: Usually occurs in terminals and positive plates, especially under overload conditions.
- Galvanic corrosion: Appears due to contact between dissimilar metals, generating local electrochemical cells.
- Leakage currents: In low insulation systems, they cause accelerated deterioration in conductive components.
In a battery, corrosion occurs due to dissolution/passivation of the active materials of the electrodes and dissolution/oxidation/passivation of the current collectors. For example, corrosion in lead-acid batteries occurs mainly on the grid of the plates, and manifests itself as a “softening and detachment” of the lead. This phenomenon is a direct consequence of the chemical conditions of the internal environment of the battery, where the electrodes are constantly reacting.
Figure 2, shows the internal aspect of a lead-acid battery affected by corrosion, where the progressive deterioration of the grids can be observed.
Case study: Corrosion mitigation of VRLA batteries in coastal environment
A study published in 2024 by IEEE analyzed the premature degradation of flooded lead-acid batteries installed in a data center located in a coastal area. Frequent failures were attributed to accelerated corrosion caused by constant exposure to salt spray and cyclic high humidity conditions. This combination rapidly deteriorated internal terminals and grids, compromising the conductivity of the system2.
In response, specific anticorrosive coatings and an environmental control system with regulated ventilation and monitoring of critical variables such as pH and internal resistance were implemented. These measures reduced failure events by 60% during the 12 months following the intervention, validating the effectiveness of a proactive approach in highly aggressive environments.
Thermal safety: Causes, effects and prevention
Thermal safety in stationary batteries is a critical aspect for their reliable and safe operation, especially in industrial or mission-critical environments. Thermal events can be caused by multiple interrelated factors that, if not properly managed, lead to dangerous reactions uncontrolled exothermic.
A frequent cause is electrical overload or misconfiguration of the charging system, which leads to excessive energy accumulation and internal heat generation. This situation can deteriorate the active materials and trigger accelerated degradation processes.
Another factor is electrolyte degradation, which is intensified by elevated temperatures. As the electrolyte loses chemical stability, the internal resistance of the cell increases, life cycles are reduced and parasitic reactions that release heat are favored.
The most critical phenomenon is thermal runaway, a self-accelerating exothermic reaction in which the heat generated by the cell cannot be dissipated in time. This further raises the temperature, causing a chain of reactions that can result in fire or explosion, particularly in lithium-ion batteries.
Failure prevention against corrosion and thermal hazards
The reliability of stationary batteries depends to a large extent on the ability to anticipate, detect and mitigate the mechanisms that generate both corrosion and thermal events; hence the importance of the development of new technological and regulatory approaches that act in a complementary manner3.
To prevent corrosion, it is important to consider the use of advanced alloys in the design of stationary batteries, such as lead-calcium-tin grids, which offer greater resistance to oxidation compared to traditional lead-antimony grids. In addition, protective coatings, such as conductive paints and epoxy coatings applied on terminals, extend the life of exposed metal components.
The incorporation of integrated sensors allows real-time monitoring of critical variables such as temperature, humidity, sulfate presence and electrochemical potential, which strengthens preventive maintenance strategies. In addition to the use of smart modules, which include diagnostic chips and memory to record critical events and facilitate the traceability of failures.
At the same time, the prevention of thermal risks is based on the use of thermal management systems (BMS) capable of regulating temperature through adaptive algorithms that adjust the load according to environmental conditions. This is in addition to materials with high thermal conductivity, liquid cooling systems and over-temperature cut-off devices. Adequate ventilation and thermally efficient cabinet design are essential for controlled heat dissipation.
The implementation of international technical standards such as UL 9540A and IEC 62619 ensures that the systems meet strict safety standards, particularly with regard to thermal propagation and the structural integrity of the batteries.
Finally, data-driven predictive maintenance in batteries is a key tool that combines remote monitoring using IoT technologies, electrochemical impedance analysis (EIS), predictive modeling with artificial intelligence and the use of digital twins that simulate the behavior of stationary batteries in different operating scenarios.
This convergence of innovation in materials, intelligent management and advanced regulations allows not only avoiding failures, but significantly extending the operational lifetime of stationary energy storage systems.
Conclusion
The reliability of stationary batteries is directly linked to the understanding and control of corrosion processes and thermal hazards. Advances in resistant materials, intelligent design and predictive monitoring are redefining safety and durability standards in the industry. The adoption of these innovations, together with a regulatory and preventive approach, is key to ensuring efficient and safe energy storage in critical scenarios.
References
- Wang, Y.-Y., & Zhang, X.-Q. (2022). Mechanism, quantitative characterization, and inhibition of corrosion in lithium batteries. Nano Research Energy, 2(1). https://doi.org/10.26599/NRE.2023.9120046
- Hildebrand, S., Eddarir, A., & Lebedeva, N. (2024). Overview of battery safety tests in standards for stationary battery energy storage systems. IEEE.
- Coughlin, M., Jones, D., Sagar, M., Cassani, L., & Willoughby, P. (s.f.). How battery technology will address the power demands of the changing data center landscape. EnerSys. Recuperado de https://www.enersys.com
