An electric vehicle battery is a battery that can be charged and used to power the electric motors of a battery electric vehicle (BEV) or hybrid electric vehicle (HEV). These batteries are usually lithium-ion batteries designed to provide high power compared to their weight and store a large amount of energy. Compared to liquid fuels, most battery technologies today store less energy for their size. This can make vehicles heavier or reduce how far they can travel on a single charge.

Li-NMC batteries, which use a mix of lithium, nickel, manganese, and cobalt, are the most common in electric vehicles. Another type, the lithium iron phosphate battery (LFP), is becoming more popular. In 2023, LFP batteries made up 41% of the global market for BEVs by capacity. LFP batteries are heavier than Li-NMC batteries but cost less and are more environmentally friendly. Some car companies are now using sodium-ion batteries, which do not require rare materials.

The battery is a major part of the cost and environmental impact of an electric vehicle. As the industry grows, there is increasing focus on ensuring battery materials are obtained in fair and responsible ways, which has become an important issue for countries worldwide. Reducing the use of mined cobalt, which is also used in fossil fuel refining, has been a major research goal. New battery designs, such as solid-state batteries, are being tested in labs and can store more than 800 watt-hours per kilogram.

In 2019, the cost of electric vehicle batteries dropped by 87% per kilowatt-hour. In 2023, the demand for EV batteries exceeded 750 gigawatt-hours. EV batteries have much higher storage capacity than the batteries used in gasoline-powered cars for starting, lighting, and ignition. The battery capacity of available EV models in 2023 ranged from 21 to 123 kilowatt-hours, with an average of 80 kilowatt-hours.

Electric vehicle battery types

As of 2024, lithium-ion batteries (LIBs) with types such as Li-NMC, LFP, and Li-NCA are the most common in battery electric vehicles (BEVs). In 2023, the total global production of these batteries reached nearly 2000 GWh, with 772 GWh used for electric vehicles. Most of this production happens in China, where capacity increased by 45% in 2023. Lithium-ion batteries are preferred for EVs because they have high energy density and long lifespans. These batteries were first used in laptops and consumer electronics. Newer EVs use variations of lithium-ion chemistry that improve fire safety, environmental friendliness, and charging speed, even if they slightly reduce energy or power. For example, lithium-ion cells with single-wall carbon nanotubes (SWCNTs) last longer because they are stronger and resist damage better.

Lithium nickel manganese cobalt oxides (Li-NMC) are widely used in BEVs since the 2010s because they perform well. However, mining the minerals needed for these batteries harms the environment. Traditional NMC batteries have problems, such as poor performance in cold weather and when they age. They also have a risk of fire if damaged or charged incorrectly. Early versions of these batteries did not work well in very cold conditions, but heaters can help in some climates.

Lithium iron phosphate (LFP) batteries are cheaper, safer, and more environmentally friendly than Li-NMC batteries. They do not need manganese or cobalt, which are rare minerals. Since 2023, LFP batteries have become the main type in China, but they are used less in Europe and North America, where their market share is below 10%. LFP batteries are also the most common type for storing energy in power grids.

Lithium titanate (LTO) batteries are known for their safety and ability to work in a wide range of temperatures. These batteries can last for over 10,000 charge cycles and charge quickly. However, they have lower energy density compared to other lithium-ion batteries.

Sodium-ion batteries avoid using rare materials. Sodium is found in salt water, so these batteries are expected to be less expensive. In early 2024, Chinese companies began producing sodium-ion batteries for small EVs, such as bikes and three-wheelers. By 2026, these batteries will be used in larger vehicles, like the Changan Nevo A06.

Other battery types are being developed:
– Solid-state batteries may offer higher energy density and better safety.
– Lithium-sulfur batteries could meet high performance needs.
– LMFP batteries are a type of LFP battery that includes manganese in the cathode.

In the 20th century, most EVs used flooded lead-acid batteries because they were reliable, available, and inexpensive. These batteries powered early EVs like the 1996 EV1. There are two types of lead-acid batteries: starter batteries for cars and deep-cycle batteries for continuous use in vehicles like forklifts. Deep-cycle batteries are also used in recreational vehicles but need special charging methods. Discharging them below 50% can shorten their lifespan. Flooded lead-acid batteries require checking electrolyte levels and adding water, which evaporates during charging. EVs with these batteries can travel up to 130 kilometers (81 miles) on a single charge.

Nickel-metal hydride (NiMH) batteries are a mature technology. They are less efficient than lead-acid batteries but have higher energy density. When used correctly, they can last a long time, as seen in hybrid cars and older Toyota RAV4 EVs that still work well after many miles. However, they do not perform well in very cold weather. GM Ovonic made the NiMH batteries used in the second-generation EV-1. Early NiMH-EVs could travel up to 200 kilometers (120 miles).

Sodium nickel chloride, or "Zebra" batteries, were used in EVs from 1997 to 2012. They use a molten salt as an electrolyte and have a specific energy of 120 W·h/kg. These batteries need to be heated to operate, which increases energy use and costs. They are non-toxic and can last for thousands of charge cycles. However, they have low power output and require high temperatures, which can waste energy and create storage challenges.

Other early EV batteries included:
– Nickel-cadmium batteries.
– Nickel-iron batteries used in the Detroit Electric.
– Lithium vanadium oxide batteries used in the Subaru prototype G4e.

Battery architecture and integration

• Cell to Module (CTM) – battery cells are placed into modules, then into a battery pack
• Cell to Pack (CTP) – battery cells are directly placed into a battery pack without using modules
• Cell to Chassis (CTC) – battery cells are placed into a vehicle's frame or chassis; batteries may be used as part of the vehicle's structural integrity or to increase its strength
• Cell to Body (CTB) – battery cells are placed into the vehicle's body

Supply chain

In the first step, materials are mined in various places around the world, such as Australia, Russia, New Caledonia, and Indonesia. After this, China plays a major role in most of the following steps. Once the materials are processed in factories, battery manufacturing companies purchase them, create batteries, and assemble them into packs. Car manufacturers then buy these packs and install them in vehicles. To reduce the environmental impact of this process, the supply chain is working to focus more on sustainability. This includes efforts to use fewer rare-earth minerals and improve recycling methods.

There are three main steps in making EV batteries: creating materials, making battery cells, and putting them together. These steps are shown in a graph using colors like grey, green, and orange. This graph does not include the production of cell hardware, such as casings and current collectors. During the materials manufacturing step, active material, conductivity additives, polymer binder, and solvent are mixed. After this, they are coated on current collectors and prepared for drying. The methods used to make active materials depend on the type of electrode and battery chemistry.

Cathodes often use materials like lithium nickel manganese cobalt oxides (Li-NMC) or lithium iron phosphates (LFP). The most common anode material is graphite. Recently, some companies have started using new materials, such as silicon mixed with graphite (used by Sila Nanotech and ProLogium) or lithium metal (used by Cuberg and Solid Power).

In general, making active materials involves three steps: preparing the materials, processing them, and refining them. Schmuch et al. discussed these steps in more detail.

During the cell manufacturing step, the prepared electrode is shaped for packaging in a cylindrical, rectangular, or pouch format. After filling the electrolyte and sealing the cell, the battery is carefully cycled to form a protective layer called the SEI on the anode. These batteries are then assembled into packs ready for use in vehicles.

For electric vehicles (EVs), the end of a battery’s life depends on several factors, such as the owner’s willingness to continue using the vehicle as its range decreases, the condition of other parts in the car, and whether the car is involved in a crash. However, in studies about repurposing batteries, the end of life is often defined as when a battery’s capacity drops to 80% of its original level. This definition comes from the U.S. American Battery Consortium, which says end-of-life occurs when the battery’s delivered capacity or peak power capability at 80% depth of discharge is less than 80% of its rated capacity. One way to manage battery waste is to reuse the pack. Repurposing the pack for stationary storage allows more value to be extracted from the battery while reducing the environmental impact over its lifetime.

Battery degradation during EV operation can vary depending on temperature and charging/discharging patterns. Each battery cell may degrade differently. Currently, battery management systems (BMS) can track the health of a battery pack but not individual cells. Engineers can reduce degradation by improving thermal management systems. A method called electrochemical impedance spectroscopy (EIS) can help ensure the quality of battery packs.

Disassembling battery modules and cells is expensive and time-consuming. The module must be fully discharged before disassembly. Then, the pack must be taken apart and reconfigured to meet the power and energy needs of its new use. A refurbishing company can sell or reuse the energy from the discharged module to lower costs. Robots are being used to make the dismantling process safer.

Battery technology is not fully transparent and lacks standard rules. Since battery development is central to EVs, it is hard for manufacturers to label the exact chemistry of cathodes, anodes, and electrolytes on the pack. Also, the capacity and design of cells and packs change each year. Refurbishing companies must work closely with manufacturers to stay updated on these changes. Governments can help by setting labeling standards.

Battery costs have decreased faster than expected. This may make refurbished batteries less appealing compared to new ones in the market.

Despite these challenges, there have been successes in repurposing EV batteries. For example, second-life batteries are used in stationary storage projects for purposes like peak shaving or storing energy from renewable sources.

Although repurposing can extend battery life, EV batteries eventually need to be recycled. Currently, recyclability is not a major focus for battery manufacturers. In 2019, only 5% of EV batteries were recycled. However, recycling is important for several reasons. It helps address future shortages of nickel, cobalt, and lithium. Recycling also reduces environmental harm by minimizing mining impacts, energy use, and greenhouse gas emissions. Xu et al. predicted that without recycling, lithium, cobalt, and nickel could exceed known reserves in the future. Ciez and Whitacre found that recycling batteries can help avoid greenhouse gas emissions from mining.

Many countries lack established recycling systems for battery electric vehicles (BEVs), which increases energy use and CO2 emissions, especially in regions with limited renewable energy resources.

Efforts are being made globally to improve recycling technologies. In the U.S., the Department of Energy Vehicle Technologies Offices (VTO) has started two initiatives focused on recycling innovation and practicality. The ReCell Lithium Recycling Research and Development center brings together three universities and three national labs to develop efficient recycling methods. One notable method developed by ReCell is direct cathode recycling. Additionally, VTO offers a battery recycling prize to encourage American entrepreneurs to find solutions to current challenges.

Recycling EV batteries helps recover valuable materials like lithium, cobalt, nickel, and rare-earth elements. This reduces the need for new mining and conserves natural resources. It also lowers the environmental impact of battery production by reducing mining effects, energy use, and greenhouse gas emissions.

To better understand the lifecycle of EV batteries, it is important to analyze emissions from different stages. Using NMC cylindrical cells as an example, Ciez and Whitacre found that about 9 kg of CO2 per kilogram of battery is emitted during raw material processing and battery manufacturing under the U.S. average electricity grid. The largest portion of these

Battery cost

Battery costs dropped by 90% between 2010 and 2024 because of improvements in battery technology and production methods. Batteries make up a large part of an electric vehicle's (EV) total cost, often as much as 30-40% of the vehicle's price. Over time, battery costs have decreased because of better technology, increased production, and more efficient manufacturing. EV batteries usually come with warranties that cover a certain number of years or miles, showing confidence in their long-term reliability.

The cost of lithium-ion battery packs is a major challenge for making battery electric vehicles (BEVs) affordable compared to vehicles powered by gasoline engines. About 70% of a battery’s total cost comes from the materials used in its cells, with cathodes alone making up 40-45% of this cost. The prices of raw materials like nickel and cobalt often change, which affects the cost of cathode materials and, in turn, the overall battery cost.

Newer models calculate battery costs based on the prices of raw metals instead of using fixed prices for cathode materials. This method shows how changes in cobalt and nickel prices influence the cost of materials like NMC, NCA, LMO, LNMO, and LFP. Using cathodes with higher nickel content, such as NMC811 and NCA, has helped lower material costs by increasing energy storage and reducing the need for cobalt.

Studies show that electric vehicles with larger battery sizes (e.g., enough to travel 320 km or 200 miles) benefit from lower costs per kilowatt-hour (kWh) because of thicker battery layers and better production efficiency. For example, battery pack costs can range from about $545 per kWh for plug-in hybrid electric vehicles (PHEV10) to around $230 per kWh for BEV200 vehicles. These cost reductions are greater than those achieved through improvements in manufacturing alone.

When more batteries are produced, costs per unit decrease, but this effect slows when production reaches 200–300 MWh per year. To keep reducing costs further, larger production facilities, better manufacturing techniques, and higher use of equipment may be needed. Today, the smallest production plants can make about 2 GWh per year, but future plants may need to produce over 15 GWh per year to keep costs low and support growth in the market.

EV parity

One issue is the purchase price, and the other is the total cost of ownership. The total cost of owning an electric car is often less than owning a petrol or diesel car. In 2024, Gartner predicted that by 2027, next-generation battery electric vehicles (BEVs) will, on average, cost less to produce than similar internal combustion engine (ICE) vehicles. In China, BEVs are now cheaper than comparable combustion engine cars. This progress is supported by government subsidies in China. In the USA, tariffs are used to protect local manufacturers, while in the EU, this approach is still being discussed. These actions may slow the point at which electric and traditional vehicles have similar costs.

The weight of the electric vehicle battery limits how far the car can travel compared to traditional vehicles. Diesel and gasoline have more than 50 times the energy density of current EV batteries.

In real-world use, how quickly a vehicle can charge is more important than battery size (see recharging section). Typical EV batteries in passenger cars weigh between 300 to 1,000 kg (660 to 2,200 lb), allowing ranges of 150 to 500 km (90 to 310 miles). These ranges depend on temperature, driving habits, and the type of car.

Even if an electric car has the same range as a traditional car, buyers must be confident that charging stations are widely available and compatible with their vehicles.

As of 2024, electric ships and large planes have shorter ranges than traditional vehicles. To fully electrify shipping, standardized multi-megawatt charging systems are needed. In some cases, such as river shipping, batteries can be swapped. However, as of 2024, fully electric large planes with ranges over 1,000 km are not expected within the next decade. This means that for more than half of scheduled flights, electric planes cannot match the range of traditional planes.

Specifics

Battery packs in electric vehicles (EVs) are designed differently by various manufacturers and depend on the vehicle's needs. However, all battery packs use a mix of basic mechanical and electrical parts to perform their main functions.

Battery cells inside the pack can have different chemical types, shapes, and sizes, depending on the manufacturer's choice. These cells are connected in series and parallel to reach the needed voltage and current for the pack. EV battery packs may contain hundreds of individual cells. Each cell usually has a standard voltage of 3-4 volts, depending on its chemical type.

To help with manufacturing, large groups of cells are often divided into smaller groups called modules. These modules are then combined to form the full battery pack. Inside each module, cells are connected with welds to allow electricity to flow. Modules may also include cooling systems, temperature sensors, and other tools. These modules must stay within a certain temperature range to work best. Most modules also use a battery management system (BMS) to monitor the voltage of each cell in the group.

The battery pack includes a main fuse that limits current during a short circuit. A "service plug" or "service disconnect" can be removed to split the battery into two separate sections. When the service plug is removed, the battery’s main terminals are not dangerous for service workers.

The battery pack also uses relays, or contactors, to control how electricity is sent from the pack to the vehicle’s output terminals. Most packs have at least two main relays that connect the battery to the positive and negative terminals, which then send power to the electric motor. Some designs include extra paths for charging the drive system or powering other parts of the vehicle, each with its own relay. These relays are usually open by default for safety.

The pack also includes sensors that measure temperature, voltage, and current. The pack’s battery monitoring unit (BMU) or BMS collects data from these sensors and controls the relays. The BMS also communicates with other parts of the vehicle outside the battery pack.

Batteries in battery-electric vehicles (BEVs) need to be recharged regularly. BEVs can be charged at home using the power grid or local sources like solar panels, or at public charging stations. Energy used for charging comes from various sources, including coal, hydroelectricity, nuclear power, natural gas, solar panels, and wind.

Fast charging reduces concerns about limited travel range because it shortens the time needed to recharge at public stations. Many charging stations now offer direct current (DC) power of 150 kW or more, which can add up to 300 km of range in about 30 minutes. Charging speed depends on the station’s power and the EV’s ability to handle it. Charging usually slows down when the battery is more than 50% full. Typical fast charging powers range from 30 to 80 kW. Charging at home or smaller stations using alternating current (AC) usually takes several hours. A typical energy use is 15 kWh per 100 km, and drivers should plan breaks every 300 km.

Home charging time depends on the household electrical outlet’s capacity unless special wiring is done. In the US, Canada, Japan, and other countries with 120 V electricity, a standard outlet provides 1.5 kilowatts. In countries with 230 V electricity, outlets can provide 7 to 14 kilowatts (230 V single phase and 400 V three-phase, respectively). In Europe, a 400 V (three-phase 230 V) grid connection is becoming more common because newer homes often lack natural gas connections due to safety rules.

With proper power supplies, batteries usually last longer when charged at rates not exceeding half the battery’s capacity per hour ("0.5 C"), which takes two or more hours for a full charge. Faster charging is still possible for large batteries.

New research shows that heat and fast charging can cause lithium-ion batteries to degrade faster than age or regular use. On average, an EV battery retains 90% of its initial capacity after six years and six months. For example, a Nissan Leaf battery degrades twice as fast as a Tesla battery because the Leaf lacks an active cooling system.

A 2024 study in Nature Energy suggests that EV batteries may last up to a third longer in real-world use than in lab tests. This challenges the idea that lab tests accurately predict battery life in everyday conditions.

Charging power can connect to a car in two ways. The first is through a direct electrical connection called conductive coupling. This may use special high-capacity cables with connectors to protect users from high voltages. In the US, the SAE 1772 conductive connector (IEC 62196 Type 1) is the standard. In Europe, the VDE-AR-E 2623-2-2 (IEC 62196 Type 2) is used, which does not require a latch, reducing power needs for locking mechanisms.

The second method is inductive charging, where a special "paddle" is inserted into a slot on the car. The paddle and the car each have parts of a transformer. When the paddle is inserted, it completes a magnetic circuit to send power to the battery. Inductive charging avoids electrocution risks because there are no exposed wires. It can also reduce vehicle weight by moving charging parts outside the car. In 1998, a Toyota representative said inductive and conductive charging had similar costs, while a Ford representative argued conductive charging was more efficient.

As of June 2024, there are over 200,000 charging locations and 400,000 EV charging stations worldwide.

The range of a BEV depends on the number and type of batteries used. The vehicle’s weight, terrain, weather, and driver behavior also affect range, just like in traditional vehicles. EV performance depends on factors like battery chemistry. Lithium-ion battery-equipped EVs can travel 320–540 km (200–340 miles) per charge.

Some batteries have higher internal resistance at low temperatures, which can reduce vehicle range and battery lifespan.

With an AC system or advanced DC system, regenerative braking can increase range by up to 50% in heavy traffic.

Research, development and innovation

As of December 2019, billions of euros are planned to be invested worldwide to improve battery technology.

Researchers have developed design ideas for wireless chargers for electric vehicles. Inductively coupled power transfer (ICPT) systems use magnetic coupling to move electricity efficiently from a charging station to one or more electric vehicles without direct contact.

Europe plans to invest heavily in the development and production of electric vehicle batteries. Indonesia also plans to produce electric vehicle batteries by 2023 and has invited Chinese companies, GEM and Contemporary Amperex Technology Ltd, to invest in its battery industry.

Electric double-layer capacitors, also called "ultracapacitors," are used in some electric vehicles, like AFS Trinity's concept model, to store energy quickly. This helps keep batteries safe from overheating and increases their lifespan.

Commercial ultracapacitors have low energy storage capacity, so no electric cars currently use them as the sole energy source.

In January 2020, Elon Musk, CEO of Tesla, said that improvements in lithium-ion battery technology have made ultracapacitors unnecessary for electric vehicles.

On May 2, 2022, President Biden announced a $3.16 billion plan to increase battery manufacturing and recycling in the United States. This effort aims to reduce reliance on gas-powered cars and increase the production of electric vehicles. The goal is for half of all U.S. car production to be electric by 2030.

The Inflation Reduction Act, passed on August 16, 2022, provided incentives for clean energy manufacturing. It offered a $7,500 tax credit for electric vehicles with batteries made in the United States and supported electric vehicle factories. By October 2022, billions of dollars in investment had been announced for over 20 U.S. battery plants. Some people began calling the Midwest the "Battery Belt" because of this growth.