Enertec elaborates on why lithium ion technology was developed

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15th Jun, 2022

The fast pace of technological growth over the last century has often been held back by the battery technology available at the time. This makes sense because devices can only be as small and efficient as the batteries that sustain them.

Lithium-ion batteries were developed because of a growing need for high capacity, long-lasting and reliable rechargeable batteries, and they have been well-known for meeting these criteria better than any other battery technology on the market today.

When looking at the technological, economic, and environmental climate over the last century, it becomes quite clear that an advancement like lithium-ion technology was only a matter of time.

Older battery technologies, including lead-acid and nickel-based batteries, have often come with major drawbacks such as high maintenance requirements, environmental concerns, and lower cell energy densities. Previous versions of lithium-ion technology were not rechargeable and presented many safety concerns.

 

A breakthrough in battery technology

Lithium-ion battery technology has been a major breakthrough for many different industries globally. It has changed the world by allowing electronics to become increasingly lighter, smaller, and more complex. With these batteries being safely rechargeable and able to deliver high capacities of energy, it is no wonder that they are used in a wide range of applications, from cellphones and laptops to large-scale renewable energy.

Before the 1970s, reliance on fossil fuels was generally unquestioned. The 1970s oil crisis, however, began to change attitudes towards energy generation and storage. Amidst fuel shortages and surging fuel prices, scientists began to look at energy alternatives in the face of a future with limited or no access to fossil fuels.

The same time period also saw the emergence and rapid growth of the environmental movement. Because of this, more emphasis than ever was placed on finding renewable energy sources. This put more pressure on researchers to come up with a compatible battery solution that was more efficient, long-lasting, and able to store large amounts of energy.

 

What were the first types of applications lithium-ion batteries were used for?

Because of the amazing properties of this technology, such as high cell energy density, long lifespan, and superior charge retention, they were perfect to replace other battery technologies for increasingly small and complex applications.

Nickel-based batteries, which had previously dominated the market for small electronics, have drastically shorter lifespans. This is mainly because they require a full discharge before being charged. Otherwise, they will begin to experience a memory effect where capacity is permanently lost over time. This makes them very inconvenient to care for properly. Lithium-ion revolutionised the market as a high-capacity battery with a long lifespan and no memory effect.

 

Where and when were lithium-ion batteries first introduced?

Sony was the first to introduce rechargeable lithium-ion batteries in 1991 for its consumer electronics. These batteries are famous for revolutionising Sony’s video cameras, as they were small and light enough to allow for the first handheld video recorders to hit the market.

Soon after this, other manufacturers adopted lithium-ion technology for consumer applications in cell phones, laptops, memory backup devices, and other small electronics. You would recognise them as the standard coin-size and cylindrical AA or AAA batteries still in use today.

Over time, newer versions of the technology were adapted for a wide range of different applications. Despite their original use in electronics, they can be used for cars, trucks, boats, and other start/stop vehicle applications such as golf carts and motorcycles. Lithium batteries now dominate the Electric Vehicle (EV) market.

Huge modular rigs are even used for Energy Storage Systems (ESS) for renewable power plants, and on a smaller scale, they are perfect for smaller home and commercial backup and solar systems.

 

What is the difference between lithium and lithium-ion?

Pioneering scientists have been experimenting with lithium-based batteries since the early 1900s, but earlier versions were not without their issues, especially considering the applications we use them for today.

To establish one of the key differences between lithium and lithium-ion batteries, it will be important to first discuss the difference between a primary and secondary cell.

 

The difference between primary and secondary cells

Primary cells are generally considered non-rechargeable cells. They have a high energy density and get discharged slowly. These cells have a high internal resistance, which means that they heat up faster and also deliver a lower voltage.

To charge these cells, they would have to be charged for a very long time at a low voltage, and they would only be able to be reused for a few cycles. They are much more volatile during charging, as they heat up and release gases during the process. This is why most primary cells are discarded after a single use.

Secondary cells are also known as rechargeable cells. They have a much lower energy density and generally consist of molten salts and wet cells. Their internal resistance is lower, so they can deliver higher voltages without overheating. The chemical reaction is easily reversible, which makes them much more practical and safe for a battery that will be recharged for many cycles.

A battery consists of positive and negative electrodes, and a solution called the electrolyte. Electrical currents are produced in batteries because of an electrochemical reaction happening at the electrodes inside the battery's cells. Positively charged ions are transported through the electrolyte from the negative to the positive electrode. For charging to occur, this process has to be reversed.

 

Lithium Batteries

Lithium batteries, also known as lithium-metal batteries, are primary cell batteries with a lithium metal cathode. Because of the chemical instability of lithium metal, recharging them is very problematic. Reversing the initial reaction damages the electrodes and also causes unwanted volatile reactions. Although they have a much higher energy density, they are heavier and present all the problems that primary cells have with recharging.

 

Lithium-ion Batteries

Lithium-ion batteries were a solution to the problems faced during the development of lithium batteries. Although the concept of using a lithium-based cathode is similar, drastic improvements were made by introducing a cathode made from a more stable lithium compound instead of using solid lithium metal. Recharging became much safer and easier, and the batteries themselves were more lightweight and efficient.

The major breakthrough that allowed for them to work effectively is a process called intercalation, where the ions can be inserted into the molecules in the electrodes. This means that the ions are able to easily move in and out of the structure of the electrodes, allowing for smooth charging and discharging. Before this, safe and reliable recharging would not have been commercially possible.

 

Do the advantages of this technological advancement in energy generation outweigh any disadvantages?

When weighing lithium-ion against other battery technologies, the advantages of this battery technology far surpass that of all variations of lead-acid and nickel-based batteries on the market.

Because of ongoing development in lithium-ion technology, many of the problems researchers originally encountered are now being resolved with intelligent solutions.

 

The advantages of lithium-ion batteries

  1. High energy density
    The energy density of lithium-ion batteries, when coupled with their charging capabilities, makes lithium-ion the battery technology of choice for applications requiring high power consumption over longer periods, in between charges.
    This also makes them perfect for backup systems, electric vehicles, and power tools, all of which require high-quality, reliable energy sources.

 

  1. Low self-discharge rates
    Charge-retention, or self-discharge, is the rate at which a battery is able to hold its own charge while not in use. Lithium-ion cells experience a much lower self-discharge rate than other battery technologies, increasing their reliability.

 

  1. Lower maintenance requirements
    Many batteries require active maintenance to ensure their longevity.
    We know that nickel-based batteries experience the memory effect when maintained incorrectly. Lead-acid batteries begin to experience sulphation damage when their charge drops too low. This is where sulphate crystals start to form around the lead plates inside the battery, eventually causing permanent damage to the cells of the battery.
    Lithium-ion batteries do not experience sulphation or memory effects, making them much more forgiving for a number of applications.

 

  1. Superior load characteristics

    Load characteristics refer to the relationship between the values of variables such as voltage, current, and depth of discharge when the supply voltage is kept constant. The depth of discharge is the percentage of the battery’s capacity that has been drained in comparison to its total capacity.
    If we look at the relationship between depth of discharge and the battery voltage of lithium-ion batteries when compared to lead-acid batteries, it is clear that they perform much better as they are discharged. There is very little voltage drop as they drain, and a significant drop in the battery’s voltage is only experienced towards the end of the battery’s life in that cycle. Lead-acid batteries experience a consistent drop in voltage as the battery is used.
    This incredible benefit means that your battery’s performance will remain consistent as it is used, right up until the battery is almost completely drained.

 

  1. Higher cell voltage
    Lithium-ion batteries can be made much smaller and more efficient due to the higher voltage of their individual cells. This allows for fewer cells required per unit, meaning that they can deliver the same amount of voltage as another battery type with fewer cells.

 

  1. No priming requirements
    Some batteries require priming when they receive their first charge. Lithium-ion batteries have the benefit of being a “plug and play” technology, where they can be used after purchasing without needing a long charge beforehand.

 

  1. Adaptable technology
    Because there are so many different variations of lithium-ion cells, lithium solutions can be tailored for their application. For example, more energy-dense cell varieties are perfect for small devices, whereas larger applications such as power tools and electric vehicles would benefit from cell chemistries better able to provide higher current levels.

 

  1. Easier on the environment
    Lithium-ion batteries do not contain toxic materials such as cadmium and lead and are generally not considered an environmental hazard except when containing toxic heavy metals or disposed of in large quantities. Lithium is generally not expected to bioaccumulate (build up in wildlife and plants), and its human and environmental toxicity is low.

 

The disadvantages of lithium-ion batteries

  1. Require a battery management system
    Care needs to be taken with lithium-ion batteries to ensure that they are not overcharged or discharged too much. Although they do not experience sulphation or memory effects, they are still vulnerable to electrode damage when frequently charged or discharged incorrectly. They can also be sensitive to extreme temperatures and need to be charged at the correct temperature.
    A battery management or circuitry protection unit is essential in ensuring that your battery is maintained optimally. Fortunately, the Enertec Lithium range comes with a built-in battery management system, taking the guesswork out of battery maintenance.

 

  1. Cost
    One of the main reasons why people do not buy lithium-ion batteries is because of their cost. However, their price has been dropping as manufacturers have been able to operate at bigger scales. As the technology becomes more widely available, costs should continue to come down over time.

 

  1. Transportation and storage
    Lithium-ion batteries can be dangerous when transported or stored incorrectly. There are regulations regarding temperature control and packaging when transporting them, and most airlines limit the number of lithium batteries they will allow on board.
    Special certification is also required to transport them, so it is important to check with your supplier to ensure that the batteries you purchase come with the relevant documents.

 

We can clearly see that lithium-ion technology has solved many of the problems that came with previous generations of battery technology. With it going on to dominate so many markets, especially in renewable energy and EVs, it is evident that many industries see it as a big part of the future. At Enertec, we have taken great care to source a reliable range to keep you on top of all these advancements. Contact us today or visit our website for more information.