Born over a century ago and still in service, the true cutting-edge technology in vehicles - lead acid battery

Many might wonder, isn't the prevalent battery for new energy nowadays the practical lithium battery? Such is the situation. Whether it is lithium-sulfur or lithium-air, these batteries are energy storage options, but a considerable portion of the initial power generation still relies on lead-acid batteries.

Can you picture that the telegraph was invented centuries ago, and after all this time, we still make extensive use of it. This is undoubtedly a "groundbreaking technology" in communication, but we have grown accustomed to it as time has passed. On the other hand, it also highlights the practicality of this technology. In fact, technology is like this. Technologies such as quantum computing that seem extraordinary now will become commonplace in the future.

Following the emergence of lead-acid batteries, they were utilized in automobiles during the 1880s. These batteries are capable of providing the significant current necessary to start the internal combustion engine – up to 400A for a duration of 3 seconds in cold conditions. Additionally, the entire electrical subsystem of vehicles powered by internal combustion engines is designed to be sustained by 12V batteries when the engine is off. By the 2000s, the automobile industry began its electrification journey. Hybrid cars still require lead-acid batteries. Now as we are starting to enter the era of electric vehicles, lead-acid batteries still persist. Many people may ask, with such a large lithium battery in electric vehicles, is there still a need for lead-acid batteries?

Indeed, the power system of an electric vehicle consists of two distinct parts. The first is a battery, typically a 12V lead-acid one, while the second is the main power battery, which mainly employs high-capacity lithium manganese oxide or lithium cobalt oxide batteries in the current market.

The primary power source is undoubtedly a large-sized lithium battery. However, when this default power battery is non-functional, a relay is needed to activate it. This crucial relay gets its power from a 12V low-voltage battery, and many of these batteries are still of the lead-acid type. Fundamentally, the basic unit of a lead-acid battery is a cell; each cell comprises a positive electrode, a negative electrode, and a separator placed between them.

A layer of black lead dioxide adheres to the surface of the positive plate. This layer of lead dioxide is composed of lead particles combined with oxidation. Between these particles, the electrolyte can freely pass through. The reason for grinding the positive material into fine particles is that it can increase the contact area with the electrolyte, which can enhance the area of reaction and thereby reduce the internal resistance of the battery.

The negative plate is a spongy lead plate with a dark black color. The electrolyte is a diluted aqueous sulfuric acid solution with a concentration of 25% – 35%. The two electrodes are placed in parallel as closely as possible to ensure they do not touch, and then a separator made of insulating materials is added between the two electrodes. This type of separator is perforated with small holes, which can not only guarantee the passage of the electrolyte but also prevent the contact between the two electrode plates.

The types of separators are roughly classified into synthetic rubber fiber separators and ceramic fiber separators. When a load is applied across the terminals of the battery, electrons start to flow in the external circuit, thereby generating an electric current. Simultaneously, within the battery, chemical energy is transformed into electrical energy. This transformation occurs as ions move from one electrode to the other. During discharge, the positive electrode undergoes a reduction reaction, providing electrons to the external circuit. In a complementary process, the negative electrode undergoes... In a complementary process, the negative electrode undergoes, losing electrons. The electrolyte plays an essential role by offering a nourishing liquid environment that enables the smooth passage of ions from the positive to the negative electrode and vice versa. This action makes the electrolyte the conduit for ion movement, ensuring the continuous supply of electrical energy within the battery.

As we wrap up our examination of EFB lead-acid batteries, it becomes clear that they mark a crucial stage in the development of automotive power solutions. These advanced batteries not only pay tribute to the long-standing tradition of lead-acid technology but also ensure that the core values of dependability and durability are carried forward into the contemporary landscape of hybrid, electric, and smart vehicles. The integration of EFB technology has ensured that lead-acid batteries remain relevant, enhancing both the performance and lifespan of power systems that drive us towards the future.