Materials Used to Make a Lithium Car Battery

Rapid expansion of electric vehicles (EVs) has increased demand for raw materials used to manufacture lithium batteries, necessitating their source from virgin minerals – this poses both environmental and social concerns.

Lithium battery chemistries differ in terms of how much energy they can store and the number of times they can be recharged, making choosing one for your particular application crucial.

Lithium-ion chemistry

Lithium-ion batteries have quickly become one of the go-to technologies in consumer electronics such as cellphones and laptops, with hybrid cars also using them becoming increasingly prevalent. Their high energy density enables a greater amount of power to be stored in smaller spaces than with traditional battery technologies.

Li-ion batteries can also be operated safely when operated within specific safety guidelines. Although their risk of fire is lower than lithium metal batteries, improper handling could still pose dangers.

Lithium-ion batteries operate via intercalation and extraction, with lithium ions moving back and forth between anode and cathodes, creating an electrolyte solution composed of non-aqueous solvents such as ethylene carbonate or propylene carbonate that envelops them both. Moisture should never enter this battery due to lithium’s strong affinity with water.

Discharging occurs when lithium ions move from the anode and into an electrolyte solution, where they are released from their binding sites by electric current and are then freed of their bonds with an anode – freeing electrons to flow freely via external wires for work to be accomplished.

Lithium-ion batteries offer many advantages over their counterparts, including good energy efficiency and high power-to-weight ratio, low self-discharge rate, long service life and portable design. Lithium cobalt oxide technology enables increased energy density than its alternatives in lithium-ion car batteries.

Electrolyte

Electrolytes are vital minerals essential for our bodies’ hydration levels and cell functions, as well as overall health benefits like fatigue, dizziness and headaches prevention. Lack of electrolytes could even lead to dehydration that impacts life significantly and disrupts daily routines in profound ways.

Lithium-ion batteries rely on non-aqueous electrolytes to avoid water reactions and protect their electrodes from degradation. They often include organic carbonates such as ethylene carbonate or propylene carbonate with complexes that bind lithium ions in solution; this liquid electrolyte then allows ions to move between anode and cathode electrodes, producing electrical energy.

As lithium ions move from anode to cathode through the electrolyte during discharge, they undergo an insertion or intercalation process that transfers their electrons from cathode. This creates an output of chemical energy stored within external circuit of cell; during charging these same ions recombine with their electrons to form electricity.

Dinca and his team are working on developing alternative battery materials that contain less cobalt, such as sodium or magnesium. Such batteries could make batteries lighter and cheaper, making them more appealing to consumers. Cobalt-free batteries should have better cycle life, recyclability and may even be safer to transport and store than cobalt ones.

Cathode

The cathode is one of the core components of lithium batteries. Acting as an electrical conductor, it facilitates lithium ions moving between anode and cathode during discharge/charging processes. Cathodes may be composed of different materials like lithium transition metal oxides, vanadium oxides, manganese-based oxides or lithium phosphates that allow for reversible intercalation/de-intercalation of lithium ions during discharge/charging cycles.

An anode is a negative electrode, responsible for discharging electrons to an external circuit during cell discharge. Conversely, cathodes combine positively charged lithium ions with electrons in an electrochemical reduction reaction at their positive electrode. Electrolyte serves as an intermediary in terms of transport of lithium ions and electrons between anode and cathodes; it does not participate in electrochemical reaction itself.

Many different cathode materials have been developed; the three most prevalent in current production can be summarized into LiCoO2, LiMn2O4, and LiFePO4. Each utilizes lithium-ion chemistry; however, their charge capacity and cycling stability vary between models.

Lithium-ion batteries depend on their cathodes for both energy density and cycle life, as this component stores large amounts of lithium ions with high conductivity and has to store large amounts of them to function optimally. To further decrease resistance and enhance performance, various conductive additives like carbon black (CB), amorphous carbon (AC), or carbon fibers (CF) may be added as conductive additives; Table 2 presents results of these additives on discharge capacities and cycle performances of various cathode materials with various conductive additives compared.

Anode

Lithium-ion batteries’ viability is greatly determined by their electrode materials – also known as anodes and cathodes – which play an essential role in energy density and voltage range regulation. Most lithium batteries utilize carbon anodes and cathodes; however, researchers are exploring alternative solutions.

Discharge occurs when an anode releases lithium ions to the cathode through intercalation, creating current and power. On charging, however, the reverse occurs. Instead of discharging lithium ions onto the cathode through intercalation, they enter an electrolyte (made up of lithium salts suspended in dimethyl carbonate solvent). From here they travel back toward anode and eventually back out through this solution to complete their circuit backwards.

Standard graphite anodes cannot be used long-term as repeated lithium insertion causes it to break apart and lose capacity, leaving no functional LIB cells. Alternatives have been proposed such as metal hydroxides; however, their high intercalation voltages reduce energy density of these batteries.

Amprius, a company that specializes in battery materials, has developed an anode with a silicon shell that encases silicon nanowires as one potential solution. Already tested in an Airbus Zephyr S pseudosatellite battery pack for test purposes, its performance was outstanding: lasting hundreds of charge cycles while producing over 435 W h/kg of energy output.

Electrode separator

The separator is an essential component of lithium batteries, serving to isolate positive and negative electrodes while still permitting lithium ion flow. Constructed using a porous membrane made of various polyolefin materials like polyethylene or polypropylene, its size affects how much current can be drawn during discharge as well as determining stability during cycling.

Porosity of the separator should be sufficient to allow lithium ions to freely move between electrodes, with wide distribution of pores that close when the battery is unplugged or shut off; optimal pore sizes range between 30 and 100 nanometers. Furthermore, its conductivity must also be high.

The wettability of a separator is also essential; it must absorb an adequate amount of electrolyte into its pores during cell operation, without dendrite formation and SEI growth occurring. A variety of separator materials may be employed such as nonwoven PP, microporous monolayer PP, cellulose, glass fiber, PTFE or trilayer PP/PE/PP; some have enhanced properties, such as increased resistance to oxidation or affinity/wettability with electrolytes; these improvements contribute significantly towards battery safety and longevity.

Current collectors

Current collectors are an essential component of lithium batteries as they allow electrons to flow between cathode and anode electrodes, helping the battery achieve high energy density and improving safety and performance. They must be designed to withstand high operating voltages without corrosion of its electrodes.

Metals such as aluminum and copper are often utilized as current collectors due to their relatively inexpensive nature and excellent electrical conductivity, yet brittleness requires large thicknesses in order to maintain mechanical integrity.

NREL scientists have come up with a novel way of decreasing current collector thickness while increasing energy density. The method involves coating active materials from lithium battery separators with adhesive, creating thin yet lightweight current collectors which will help make lithium car batteries more energy-efficient.

Scientists are exploring methods of decreasing the thickness of current collectors while simultaneously increasing their electrochemical stability. Carbon-based materials offer more environmentally friendly production processes compared to metal ones and are being increasingly utilized as current collectors.

Carbon-based current collectors offer many advantages over their more rigid counterparts, including being lighter and flexible enough to improve battery’s energy density and power capacity – an increasingly essential requirement given lithium-ion’s rising popularity.