The automotive industry has continued to develop various alternative fuel vehicles in response to growing environmental concerns as well as limited oil resource availability. Battery electric vehicles (BEVs) are one of the most common and widely used non-petroleum-based solutions. BEVs have zero emissions, which is one of their main advantages (generating no greenhouse gases or pollutants). As a result, BEVs contribute to cleaner air and are more environmentally friendly. Furthermore, these vehicles run on electricity, which can be generated in more environmentally friendly and renewable ways.
There are numerous models of commercially successful BEVs on the road, ranging from the less expensive Nissan Leaf to the high-end Tesla Model S. Furthermore, due to significant investments in infrastructure support, battery electric vehicles have become a highly viable and viable option in the automotive market for consumers. Unlike traditional internal combustion vehicles powered by petroleum, BEVs are propelled by a large electric motor that is powered by a rechargeable onboard battery system.
While the majority of BEV production models use the same type of EV battery, several different types of EV batteries have been used in battery electric vehicles.
What are Batteries and What it does in EV?
When compared to ICE vehicles, EV motors react quickly and have high torque. Several commercially successful EV models are available. Whether it’s a sports model or an economical model, they’re both available today. The performance of an EV is directly related to the design of the battery pack. So we’re all aware of how batteries are used in almost all of the appliances we use daily, as well as in our automobiles. With chemical energy stored in a battery, energy is converted to electricity.
The negative electrode of the battery contains an excess of electrons, which are negatively charged subatomic particles. When the two are connected by an electrical cable, electrons flow from the negative to the positive. Companies have developed a method to use the energy generated by these moving electrons to power a motor. It must deliver enough current to the motor over time because it powers the vehicle’s engine.
Does this battery have a shelf life? Unfortunately, the battery has a limited lifespan and will need to be replaced in a few years. You can use the battery normally until that time.
When no electricity flows between the electrodes, the battery dies. There is usually no current flow when the number of electrons on the positive and negative sides is equal. The battery expires during this time, and it must be replaced with a new one.
Lead Acid Batteries and Nickel Metal Hydride Batteries
Lead-acid batteries and nickel-metal hydride (NiMH) batteries are both well-established battery technologies. These batteries were first used in early electric vehicles like General Motors’ EV1. However, their use as the primary source of energy storage in BEVs is now considered obsolete. Lead-acid batteries, which are relatively inexpensive, have been used in conventional gasoline-powered vehicles.
However, the specific energy of this battery (34 Wh/kg) is low. When compared to lead-acid batteries, NiMH batteries are thought to be superior because they can have up to double the specific energy (68 Wh/kg). This enables electric vehicles powered by NiMH batteries to be significantly lighter, resulting in lower energy costs for BEV propulsion. Likewise, NiMH batteries consist of a higher energy density as compared to lead-acid batteries, allowing the battery system to fit into a smaller space. However, NiMH batteries have some disadvantages, such as lower charging efficiencies when compared to other types of EV batteries.
There is also a significant problem with self-discharge that is exacerbated when the batteries are exposed to high temperatures. As a result, NiMH batteries are less suitable for use in hotter climates. Furthermore, there has been legal controversy surrounding large-format NiMH batteries, which has influenced the use of NiMH batteries in battery electric vehicles.
Lithium-ion (Li-ion) batteries are now widely accepted as the industry standard for battery electric vehicles. There are many different types of Li-ion batteries, each with its own set of characteristics, but vehicle manufacturers are focusing on variants with exceptional longevity. In comparison to other mature battery technologies, Li-ion provides numerous advantages. It has high specific energy (140 Wh/kg) and energy density, making it ideal for battery-electric vehicles.
Also, Li-ion batteries work best when it comes to retaining energy, having a self-discharge rate and order of magnitude lower than the NiMH batteries. Also, there are some disadvantages to Li-ion batteries. Li-ion batteries have traditionally been high-priced battery technology. Overcharging and overheating of these batteries are also serious safety concerns. Li-ion batteries are susceptible to thermal runaway, which can result in vehicle fires or explosions.
There have been so many instances where the famous Tesla Model S, which used Li-ion batteries, has caught fire because of the issues with fluctuation in charging or damage to the battery. However, significant efforts have been made to improve the safety of vehicles powered by Li-ion batteries.
If you used rechargeable batteries in the 1990s, you are already acquainted with nickel-cadmium technology. “Ni-Cd” accumulators offered several benefits, including high storage density and a lifespan of 500 to 1,000 charging cycles. They did, however, suffer from memory effect, a physical phenomena in which the battery’s performance degrades when subjected to partial “charge-drain” cycles. Ni-Cd batteries, which were used in the construction of electric cars in the 1990s, are now outlawed owing to cadmium toxicity.
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The solid-state battery
Scientific study has long explored the notion of the solid-state battery, but it is only in the last ten years that advancement has allowed the technology to be seen as being used by the car industry in the far future.
The basic idea is to replace the battery’s liquid electrolyte with a solid substance, which can be a plastic polymer, compressed inorganic particles, or a combination of the two. In principle, this technology is all good: it increases energy density and stability while making temperature management easier. Despite this, the solid-state is still at the laboratory prototype stage. The lithium-ion battery has a long life ahead of it!
Energy is stored in a polarised liquid between an electrode and an electrolyte in ultracapacitors. As the surface area of a liquid increases, so does its energy storage capacity. Ultracapacitors can supply additional power to cars during acceleration and hill climbing, as well as assist in the recovery of braking energy. They may also be beneficial as supplementary energy storage devices in electric cars since they assist electrochemical batteries in balancing load power.
Hydrogen Fuel Cells
Hydrogen and fuel cells are commonly thought to be inseparable since hydrogen-fueled FCs offer the highest performance and the least environmental effect of any FC. Hydrogen is a transporter of energy rather than a primary source of energy. There are no naturally occurring pure hydrogen reserves. To generate hydrogen, water can be electrolyzed in the opposite direction as the fuel cell process. Significant quantities of power are required to compel electrolysis to occur, much of which is currently supplied by the combustion of fossil fuels.
However, not all hydrogen fuel cells are designed for use in automobiles. Stationary fuel cells for energy generation have been under research for decades. Some fuel cell uses for residential or commercial buildings might include the generation of electricity from fuel inputs such as natural gas or hydrogen, and the utilisation of waste heat from that process to heat the structure. Hydrogen atoms enter a fuel cell at an anode, where they are chemically stripped of their electrons.
Hydrogen atoms have now been “ionised,” and they have a positive electrical charge. Current flows via wires thanks to negatively charged electrons. If alternating current (AC) is required, the fuel cell’s direct current (DC) output must be channelled via a conversion device known as an inverter.