Published on 04th May 2022
A battery’s ubiquitous presence is well known in our technology-driven world. When we think of powering a watch, laptop, phone, electric vehicle, or pallet truck, it is a battery that keeps a device running for a unique purpose.
From everyday electronics and life-saving medical equipment to power grids and luxury yachts, lithium-ion batteries (LIBs) are inextricably linked to our lives in one way or the other.
Lithium-ion battery technology is the most pervasive among other battery technologies, with years of extensive R&D behind developing the world’s best-known and widely used batteries.
Lithium is believed to be a comparatively rare metal with lithium mining being a resource-intensive and risky task. Moreover, a liquid electrolyte-based lithium-ion battery is susceptible to an explosion or fire risk, and disposing of/recycling lithium-ion batteries is a challenge, too.
Lithium-ion batteries have been the go-to batteries for capability, convenience, and cost despite major disadvantages like sourcing, safety, and sustainability.
Do you want to learn more about the fascinating lithium-ion batteries? Let’s get started.
Lithium (symbol: Li) is the third lightest element with the atomic number 3. It is a soft and silvery-white alkali metal that reacts with organic and inorganic reactants in many ways.
As lithium is not found freely in nature, lithium is mined from hard rock and underground brine deposits. Spodumene is the most important lithium ore—Bolivia, Argentina, Chile, the United States, Australia, and China are the leading countries with the largest lithium reserves. Chile, Argentina, and Bolivia are famously referred to as the “Lithium Triangle”—accounting for more than 75% of the world’s lithium reserves.
What is a lithium-ion battery? A lithium-ion battery is a rechargeable battery that can be charged multiple times as a power source for electronic devices and electric vehicles and used in other applications such as stationary battery energy storage systems (BESSs) and uninterruptible power supplies (UPSs).
During the charging phase in a lithium-ion battery, lithium ions move from the positive side of the battery to the negative side. In contrast, the ions move in the reverse direction during the discharging phase.
Throughout the two phases, an insulating layer called a “separator” blocks the electrons but allows the lithium ions to pass through the electrolyte (conductive material). The movement of lithium ions between the negative and positive poles (negative electrode [anode] and positive electrode [cathode]) of the battery creates an electrical potential difference called “voltage.”
In simple terms, voltage is the amount of electrical potential a battery holds—typically measured in volts. A lithium-ion battery has a nominal battery voltage of 3.7 volts per cell.
When an electronic device is connected to a lithium-ion battery, the blocked electrons pass through the device and power it.
A lithium-ion cell serves as a power cell (delivers high current load over a short period) or an energy cell (delivers sustained current over a long period).
Within the lithium-ion battery portfolio, there are lithium-ion and lithium polymer batteries, among other lithium battery variants. Unlike a lithium-ion battery that uses a liquid electrolyte, a lithium polymer (also known as LiPo, Li-poly, and lithium-poly) battery uses a solid gel-like electrolyte.
In 1800, an Italian physicist and chemist named Alessandro Volta invented the first electric pile that was recognized as the forerunner of the modern battery. In 1817, a Swedish chemist named Johan August Arfwedson discovered lithium by isolating it as a salt. In 1912, lithium battery research began with the experiments of an American chemist, Gilbert Newton Lewis.
Lithium-ion battery research in the 1970s and 1980s continued to demonstrate improvements with the discovery of rechargeable lithium cells using lithium cobalt oxide (LiCoO2) cathodes and the graphite anode.
In 1991, Sony and Asahi Kasei launched the first commercial lithium-ion battery. Lithium-ion battery technology progressed in 1997 with a more stable polymer-based solution to ensure thermal stability. In 2002, scientists developed the first-ever laminated lithium-ion batteries for portable devices like cameras, laptops, phones, and tablets.
Lithium-ion batteries continue to evolve for small and large capacity requirements by becoming cleaner, safer, and lighter.
M. Stanley Whittingham, a British-American chemist; Akira Yoshino, a Japanese chemist; and John B. Goodenough, an American materials scientist and a solid-state physicist, were co-awarded the Nobel Prize for chemistry in 2019 for the development of the lithium-ion battery. Their work was instrumental in heralding an era of wireless electronics.
You can enjoy this podcast on the lithium-ion pioneer—John B. Goodenough—also known as the “father of the lithium-ion battery.”
The words representing Li-ion battery chemistries are identified in abbreviated letters for simplicity. The chemistry of cathode materials determines the efficacy of a Li-ion battery. Cobalt has been used as an active material in Li-ion batteries for quite some time.
However, risky sourcing of expensive cobalt raises questions on its feasibility as a battery material. Battery manufacturers have been exploring different types of lithium-ion batteries to avoid risky sourcing practices and improve cost, loading capabilities, and longevity.
A lithium-ion battery’s chemical composition plays a pivotal role in making the battery powerful, resilient, and safe for a wide variety of applications. For example, the famous EV company, Tesla, uses a lithium-iron-phosphate (LFP) battery chemistry for its standard range vehicles and the nickel-cobalt-aluminum (NCA) battery chemistry for its longer-range vehicles.
It is well known that expensive batteries that do not last long are not cost effective. Generally, the following parameters (listed in alphabetical order) define the desirability and efficiency of battery types:
Now, let us look at six common lithium-ion battery chemistries in detail:
Known since 1991
LCO at a glance (listed in alphabetical order):
Also known as a “lithium cobaltate or lithium-ion cobalt battery,” a lithium cobalt oxide battery has a graphite carbon anode and a cobalt oxide cathode with a layered structure for ion movement. The Li-cobalt battery’s high specific energy makes it a popular choice for consumer electronics, such as digital cameras, mobile phones, and laptops.
Limitations include low specific power, low safety, and low lifespan. Furthermore, applying a higher load and forcing a fast charge cause overheating and unwarranted stress in an LCO battery.
In recent years, the Li-cobalt battery chemistry (~60% cobalt) has been losing favor to other battery chemistries like NMC and NCA due to the high cost of cobalt, reduced dependency on illegal cobalt mining, and improved performance of a combination of other active cathode materials.
Among the factors listed above, what stands out is cobalt sourcing that is related to human rights abuse. DR Congo (The Democratic Republic of the Congo) provides 70% of the total cobalt supply. However, cobalt mining in the second-largest country in Africa has drawn severe criticism, with no labor laws or safety protocols for operating artisanal (small-scale) mines.
Despite cobalt being a multi-billion dollar industry, it has earned the dubious distinction of the trade in “blood batteries” because of high-risk artisanal mines, which employ child labor and work conditions that cause life-changing injuries. Cobalt-free lithium-ion batteries can help us tap into “clean” batteries made ethically without jeopardizing lives.
Applications: Cameras, laptops, mobile phones, and tablets.
Known since 1996
LMO at a glance (listed in alphabetical order):
Commonly called “lithium manganate, lithium-ion manganese, li-manganese, and manganese spinel,” an LMO battery’s architecture forms a three-dimensional spinel structure or cathode crystalline framework of lithium manganese oxide that appears after initial formation. The spinel structure improves current handling and ion flow as well as lowers internal resistance while enhancing safety and stability.
Newer Li-manganese designs have been successful in maximizing the battery for improved lifespan, safety, and specific power. Today, pure Li-manganese batteries are only used for special applications.
As blending battery chemistries improves the lifespan and specific energy, the LMO-NMC combination is chosen for many electric vehicles, such as the BMW i3, Chevy Volt, and Nissan Leaf.
How does LMO-NMC work for an electric car? While the LMO part delivers high current on acceleration, the NMC provides a long driving range.
Li-ion research has been instrumental in combining Li-manganese with other active cathode materials like cobalt, nickel, and aluminum to boost capacity, load capability, and longevity.
Applications: Medical devices, portable power tools, hybrid and electric vehicles, and powertrains.
Known since 2008
NMC at a glance (listed in alphabetical order):
An NMC battery has one of the most successful Li-ion cathode combinations of nickel-manganese-cobalt. Also known as NCM, CMN, MNC, and MCN, an NMC battery can serve as an energy cell or a power cell.
Combining the individual competencies of nickel (high specific energy) and manganese (the ability to form a spinel structure for low internal resistance) makes the NMC battery the preferred choice for e-bikes, power tools, and other electric powertrains.
The unique combination of one-third nickel, one-third manganese, and one-third cobalt (1-1-1) makes the NMC battery a good choice with a low raw material cost due to reduced cobalt content. The NMC family is growing to accommodate NMC-blended Li-ion systems for a wide range of applications like automotive and energy storage systems (ESSs) that rely on frequent cycling.
Applications: E-bikes, EVs, medical devices, and industrial.
Known since 1996
LFP at a glance (listed in alphabetical order):
The discovery of phosphate as a cathode material in 1996 led to the development of rechargeable lithium batteries with one of the well-known battery materials. Also known as “lithium ferrophosphate,” a LiFePO4 battery or LFP battery provides good electrochemical performance with greater tolerance to some overcharge and full charge conditions.
The battery’s lower nominal voltage reduces the specific energy below that of a cobalt-blended lithium-ion battery. LFP batteries are mainly used for energy storage and other applications that require a high level of safety, a large amount of power, and a long lifespan.
Advancements in battery chemistry are making replacements possible for traditionally used batteries. For example, a Li-phosphate battery can replace a lead-acid starter battery—a Li-phosphate battery works well in a series of four cells that produce a similar voltage to that of six lead-acid cells in a series.
Applications: Mainly stationary applications with high endurance.
Known since 1999
NCA at a glance (listed in alphabetical order):
NCA batteries are commonly used for EV powertrains owing to their high specific energy, impressive specific power, and a relatively long lifespan. NCA’s main disadvantages are cost, safety, and recent supply chain issues.
The NCA battery gains greater stability with the addition of aluminum. In a study that compared the specific energy of lead-, nickel-, and lithium-based systems, Li-aluminum (NCA) was found to have the highest specific energy.
NCA can deliver a relatively high amount of current for extended periods. However, a significant drawback is the low level of safety.
Applications: EVs, electric powertrains, medical devices, and industrial.
Known since 2008
LTO at a glance (listed in alphabetical order):
The Lithium-titanate battery is one of the safest Li-ion batteries with excellent performance. Compared to a conventional cobalt-blended Li-ion battery, an LTO battery exhibits zero-strain property and does not form an SEI (Solid Electrolyte Interface) film or lithium plating when charging at low temperature and fast charging.
In an LTO battery, Li-titanate replaces the graphite in the anode while lithium manganese oxide or NMC acts as the cathode material. Other notable features include thermal stability under high temperatures, fast charging, and a high discharge current (10X the rated capacity).
Applications: Aerospace and military equipment, EVs, electric powertrains, solar-powered street lighting, telecommunications systems, and UPS.
The LCO battery has been the most commonly used in small portable electronics. LMO batteries deliver higher current and operate safely at higher temperatures than LCO batteries.
NMC is the dominant cathode chemistry for many uses due to its high energy density, high thermal stability, and a longer cycle life at a lower cost than other cobalt-based batteries.
Unlike other Li-ion battery types, LTO batteries charge faster while LFP batteries are highly stable and very safe even if fully charged. NCA’s ability to perform in high-load applications with a long battery life makes it an ideal choice for electric vehicle manufacturers such as Tesla.
After learning about types of lithium-ion batteries based on battery chemistry, it’s time for a quick look at the three most popular form factors (battery structures) of lithium-ion batteries:
Also known as the “round lithium battery,” a cylindrical lithium battery is available in varying amp-hours, widths, and lengths with a high degree of automation and stable product transfer. Popular models are 14650, 17490, 18650, 21700, and 26650.
Cylindrical cells are used for small and large battery packs of different capacities and voltages. In addition, cylindrical cells are better suited for applications that factor in weight and limited space. Typical uses include AH batteries, children’s toys, drones, medical equipment, and power tools.
A prismatic cell is rectangular in shape and offers a larger capacity (packs more amp-hours per cell) by having more lithium per volume. This dimensional quality allows a prismatic cell to be a top choice for energy storage devices, larger battery packs, and single-cell options.
A pouch cell consists of an aluminum foil pouch with terminal tabs at either end. A pouch cell can pack more power density than other cells by using lithium polymer in the form of a powder. Due to their construction (flexible packaging material and structure) and size, pouch cells allow for the most lithium per volume.
Lithium-ion battery configuration is essential for specific applications, such as power tools that generate high loads/torques and motive cyclic applications like e-bikes and scooters. Custom battery pack configurations in shape, size, and flexibility level are recommended to fit starter (starter battery), high-rate, or deep-cycle application needs.
A lithium-ion battery pack comprises clusters of individual lithium-ion battery cells configured in a series, parallel, or both to deliver the desired capacity, power density, or voltage for multiple purposes.
A battery delivers an exceedingly low number of cycles in the presence of moisture. So, it is essential to monitor moisture, cold temperature, and elevated storage temperature as these factors can heavily impact battery performance.
In addition, a battery management system (BMS) is an electronic system that monitors individual cells within a battery pack, increases safety, and optimizes battery performance.
Batteries can be classified into primary (non-rechargeable or disposable) and secondary (rechargeable or reusable) batteries. In contrast to disposable alkaline batteries that use zinc and manganese dioxide, lithium-ion batteries are rechargeable batteries that use lithium metal or compounds. Moreover, a lithium-ion battery is a high-performing but expensive alternative to a standard alkaline battery.
The most commonly used rechargeable batteries are NiMH (Nickel-Metal Hydride) and NiCd or NiCad (Nickel-Cadmium) batteries. In contrast to NiMH batteries and NiCd batteries, lithium-ion batteries have a higher energy density, lower self-discharge rate, smaller size, and require less maintenance. Lithium batteries are also customizable to meet different needs.
Although each battery type has its pros and cons, let us look at the primary advantages and disadvantages of lithium-ion batteries:
Low cost per cycle, high energy density, and high specific energy make lithium-ion batteries useful for a number of applications, including:
Li-ion battery packs can act as indispensable power sources for electric, hybrid, or plug-in hybrid electric vehicles like electric bicycles, electric cars, and electric motorcycles. Some compelling advantages of using lithium-ion batteries are:
A lithium-ion battery provides nearly instant power to run or shut down the equipment in the event of traditional power loss or instability. Computers, medical equipment, and other emergency power backup systems greatly benefit from lithium-ion batteries.
Greater energy density, multiple charge cycles, and zero-to-low maintenance are some of the features that make industrial lithium battery packs ideal for electric machinery, material handling equipment, and other vehicles such as:
Lithium batteries are capable and dependable—from powering a small motor to powering a yacht. Compared to a traditional lead-acid battery, a long-lasting rechargeable lithium battery ensures reliable and lightweight marine performance.
Lightweight, small, and high energy density make lithium-ion batteries suitable for medical applications—from defibrillators and medical carts to CAT scan machines and MRI machines.
The following advantages make lithium-ion batteries ideal for mobility equipment such as electric wheelchairs and personal transporters:
Lithium-ion batteries can power camcorders, computers, digital cameras, mobile phones, portable game consoles, tablets, torches, and other portable electronic devices. Lithium-ion batteries, being lighter and smaller and able to tolerate movement and temperature changes, are durable and economically viable as portable power packs.
Cordless drills, saws, sanders, and various garden tools, such as hedge trimmers and whipper-snippers (also called “lawn trimmers” or “line trimmers”) use Li-ion batteries.
Lightweight and rechargeable lithium batteries work well for monitoring a fleet of vehicles, job sites, or remote locations where installing a permanent alarm system is not possible. As a lithium-ion battery lasts longer and is supposed to have a 10X lower discharge rate than a lead-acid battery, it is quite effective for alarm or surveillance systems.
As the use of solar energy and wind energy increases across the world, lithium-ion batteries are beneficial in charging quickly and storing higher amounts of energy. Lithium-ion batteries can make renewable energy companies maximize the potential of solar power and wind power storage.
Moreover, LFP battery packs are used for high-quality and long-lasting solar batteries that power solar-street lights.
Lithium-ion batteries are one of today’s commercially available and widely used rechargeable batteries currently dominating the secondary battery market. Over the years, different types of lithium-ion batteries gained popularity over other battery chemistries due to higher energy density, smaller size and weight, and superior rechargeability.
Although there are several lithium-ion battery types to choose from, the choice depends on the application, budget, power requirements, and safety tolerance, among other factors.
Despite certain limitations, such as lithium scarcity, high-temperature instability, and safety risk, lithium-ion batteries continue to occupy a significant position in the battery market and are expected to play a crucial role in the foreseeable future.
However, lithium-ion batteries are facing stiff competition from other batteries and energy storage technologies. During a momentous period like this, the lithium-ion battery industry is embracing innovation with agility.
Lithium-ion technology innovation is steering the path of lithium-ion batteries toward more measurable and meaningful outcomes primarily in:
While cobalt is necessary for structural stability, nickel provides greater energy density.
The transition from cobalt-rich cathodes to nickel-rich cathodes is also redefining battery innovation in the Li-ion technology space. Battery manufacturers, including established and emerging players, are investing in lithium-cell R&D to unlock the potential of newer Li-ion battery systems.
In the words of John B. Goodenough, “science is an international language.” And it is this language that will continue to foster innovation and set new benchmarks in the global lithium-ion battery market.
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