What are the types of batteries? Learn the differences between cell types!
The battery cell industry is evolving more dynamically than ever before. New battery technologies are gaining wider applications, and alongside lithium-ion cells, including LFP and NMC, and lithium-polymer cells already function in the market. We're exploring their differences, as well as their advantages and disadvantages.
The battery cell industry is evolving more dynamically than ever before. New battery technologies are gaining wider applications, and alongside lithium-ion cells, including LFP and NMC, and lithium-polymer cells already function in the market. We're exploring their differences, as well as their advantages and disadvantages.
19 November 2023
Battery cells are now used not only in laptops or toys. With the increase in energy density, they can power larger devices: from tools, through electric scooters and bikes, to e-cars as large as buses. This is possible because in all these applications, we can use the same type of cells (Li-ion). Nevertheless, work is still ongoing on new solutions. That’s why it’s worth knowing the differences between the most popular types of batteries.
First battery cells – NiCd and NiMH
The history of battery cells began in 1899 in Sweden when Waldemar Jungner constructed the first nickel-cadmium cell (NiCd). High material costs used in its production significantly limited the use of these types of batteries. An additional disadvantage was the high toxicity of cadmium. However, it took almost 100 years mainly for this reason that the sale of NiCd batteries in Europe was legally restricted only for special industrial applications.
In the 1990s, nickel-metal hydride (NiMH) cell technology emerged. In terms of construction, they differ from NiCd only in the cathode material, making them significantly more “eco-friendly.” They offer 30 to 40% higher capacity and have higher resistance to the “memory effect” than NiCd cells. Additionally, the presence of nickel increases the attractiveness of their recycling. Among the major disadvantages of NiMH cells are their significantly limited lifespan, the need for complex charging algorithms, and a large drop in performance at low temperatures.
Modern types of battery cells. How do they differ?
The development of battery cells lasted for decades, but it accelerated significantly only in the 1990s. It was in that decade that the production costs of modern batteries became lower, leading to increased usage, which in turn stimulated the development of new production technologies.
Lithium-ion cells. What’s worth knowing about them?
The discovery of the lithium-cobalt oxide battery dates back to the 1970s. John B. Goodenough built it then, using a lithium and cobalt oxide cathode. In 1991, Sony introduced the first commercial lithium-ion batteries based on LiCoO2 technology to the market.
Popular 18650 batteries
Soon after, cells such as the 18650 were developed, named after their dimensions (18 mm diameter, 65.0 mm length). Li-ion cells can also have other shapes and sizes. Their production started becoming cheaper from 2001 onwards, which ensured their enormous popularity.
Applications of Li-ion cells
On the other hand, Li-ion cells are susceptible to self-ignition and explosions under certain conditions. Hence the need for special battery management systems that ensure the stability of charging and discharging processes and protect the battery from overheating. In practice, the production process and correct usage have the greatest impact on the stability of Li-ion cells. Therefore, it is recommended to use batteries only from reputable manufacturers with dedicated charging devices.
Lithium-ion cells are commonly used in:
- Consumer electronics (phones, laptops, digital cameras, power banks, flashlights, etc.),
- Large energy storage systems for industry,
- Some electric vehicles.
Lithium-polymer cells. Why are they so popular?
Lithium-polymer cells are, in fact, lithium-ion batteries in which the liquid electrolyte has been replaced by a solid or gel-like polymer (but do not confuse them with gel batteries, where the gel electrolyte is a mixture of sulfuric acid with silica).
In the initial designs of lithium-polymer cells, the electrolyte took the form of a plastic film, whose electrical conductivity at room temperature was low. Heating the cell to a temperature between 50°C to 60°C increased its conductivity, which was mostly inconvenient in many applications. Hence, polymer cells with a gelled electrolyte were created, which have acceptable performance at room temperature.
Unlike lithium-ion cells, Li-Po batteries don’t need rigid housings, reducing their weight by over 20% and allowing for battery shapes tailored to devices. A lithium-polymer cell can be as thin as a credit card. For these reasons, they are used in laptops, smartphones, and other portable devices. Additionally, Li-Po cells are also found in mobile medical devices and remotely operated vehicles (e.g., drones).
LFP batteries, LiFePO4 – what are they?
One type of lithium-polymer cell with a gelled electrolyte is the LFP battery, also known as LiFePO4 due to the fact that its positive electrode is made of iron and phosphorus.
Currently, these are the safest batteries on the market, more resistant to mechanical damage (especially puncture). They also exhibit high resistance to improper operating conditions, making them suitable for heavy industry and other demanding applications (including deep discharge). Compared to NCA/NCM cells, they are cheaper but have lower energy density. They suffer from reduced performance at low temperatures. Properly used, they achieve a lifespan of 3500 to 5000 cycles, corresponding to a period of use from 8 to even 10 years.
LFP batteries are most commonly used in:
- Electric cars – especially in cheaper models, such as Tesla in the Standard Range version,
- Telecommunications, energy, industry, and medicine,
- Emergency power supply and alarm systems,
- Evacuation lighting,
- Photovoltaic installations,
- Onboard power supply in boats, campers, trailers,
- Increasingly in warehouse vehicles (forklifts).
NCA cells – the most important information
Panasonic produces NCA cells. This construction uses cathodes made of a mixture of nickel, cobalt, and aluminum. This allows NCA cells to operate at the highest charging rates and have high energy density (200-260 Wh/kg) but the shortest lifespan. Furthermore, their lifespan decreases not only due to usage but also due to the “aging” of the cell.
Alongside NMC, NCA cells are mainly used to power electric cars. They are also used in energy storage systems but sporadically in consumer electronics.
NMC battery cells – do you know these facts?
- Production of NMC cells started in 2009.
- Their positive electrode is made of a mixture of nickel, manganese, and cobalt.
- The proportions of these components determine the prices of these cells and their properties such as energy density (150-200 Wh/kg) or specific power.
- Compared to LFP batteries, they have a shorter lifespan (from 800 to 2000 cycles), and while they exhibit stability in the used chemical components, they are less safe than LiFePO4 cells.
- Similar to LiFePO4, NMC cells contain gel-type electrolytes but perform better at low temperatures.
- They are among the most commonly used cells in electromobility due to the compromise between energy density and safety.
NMC cells are primarily used to power:
- Electric tools,
- Phones, laptops,
- Forklifts and pallet trucks (especially the most compact models),
- Electric cars with the largest batteries (e.g., Tesla, Long Range, and Performance models).
Safe semiconductor batteries
For the safety of use, semiconductor batteries, i.e., solid-state batteries, seem most attractive. Primarily because they remove the liquid electrolyte containing hydrocarbons, which is what makes it an excellent fuel. This is why overheated Li-ion batteries burn so effectively. Solid-state batteries also have higher energy density and can operate in a wider temperature range.
I co-founded City Lion in December 2019. We manufacture and assemble battery packs for light electric vehicles. Within three years, we became the most popular European manufacturer of electric kick scooter batteries. Since 2023 we also produce electric bicycle batteries.