Skip to content

Lithium-Ion: What Is It and How Does It Work?


Powerful battery technology fuelled by lithium ions is changing the way many of us go about our jobs. But what is a lithium-ion battery and how does it work?

They’re in your phone and your laptop. Your electric toothbrush, and a growing number of medical devices. They power your doorbell camera and the golf cart you use to get across the green. You might not see a lithium-ion battery very often but they’re around you every day at home and increasingly in the workplace, where across industries they’re fuelling a new wave of innovation, sustainability, and efficiency. But how do they work? 

While you don’t need a deep, technical understanding of lithium-ion technology to keep your phone juiced and your teeth clean, an awareness of what’s going on inside a typical cell will help you to get the most out of these batteries at work, where even a basic knowledge will help you to keep your operations running, your business compliant, and your people safe.

Click to download your copy of our four-step risk assessment checklist for Li-ion batteries.

What is lithium ion? A brief history 

Lithium batteries have actually been in development since the early 1900s, but they didn’t really become commercially viable until the 1970s. These first cells weren’t rechargeable, and attempts to develop lithium batteries that could be recharged again and again revealed limitations inherent to the use of lithium, not least of which was that the battery would short. 

This actually had quite dangerous repercussions, capable of triggering thermal runaway and a large recall of the batteries from Japan in 1991 when someone was actually hurt by one.

To get around this, research began into non-metallic alternatives utilising lithium ions. While not risk free, this solution was much more stable, and in the same year that so many lithium batteries were pulled from the market, the first viable lithium-ion (Li-ion) batteries were approved for commercial use.

What is a lithium-ion battery?

Unlike its straight-up lithium predecessor, the Li-ion battery is rechargeable. Naturally, this made it a very attractive battery type with widespread applications across industries. 

Lightweight, reliable, and with the potential to be made in very small sizes, Li-ion batteries have become a commonplace source of power for a wide range of electronic devices, from the aforementioned smartphones, laptops, and household appliances to all manner of electric vehicles and even grid-scale energy storage systems. They can be charged quickly and with relative ease, and they don’t need to be fully charged before you put them to use. (In fact, it’s advisable not to fully charge them, as overcharging comes with increased risk.)

How do lithium ion batteries work?

Li-ion batteries typically contain an anode, a cathode, and a separator preventing direct contact between the two. In simple terms, this keeps the battery from short-circuiting. They also contain electrolytes and two current collectors (a positive and a negative).

Your battery’s actual design may vary depending on its make and manufacturer. In some cases, for example, a polymer foil is bound with the electrolyte on a molecular level. In these cases, there’s no need for the cell to contain a separator. 

When the battery is in use, lithium ions cross the electrolyte over to the cathode. The movement of the lithium ions creates free electrons in the anode, which creates a charge in the positive current collector. 

The electrical current then flows through the device in question to the negative current collector. When the battery is charging, this process is reversed (lithium ions are released by the cathode and received by the anode).

How long do lithium-ion batteries last without charging?

The answer to this question varies depending on various factors such as the capacity of the battery, the usage of the device, and the age of the battery. Very broadly speaking, a fully charged Li-ion battery can last for anywhere between 2-4 days without charging, depending on the usage. 

If you’re using them to power high-spec forklifts in 24/7 warehousing operations, on the other hand, you’ll notice them running out much quicker than that! 

It's important to note your battery won’t just lose its charge when in operation. Leaving the battery unused for extended periods will also drain it. It's recommended to charge the battery regularly to ensure optimal performance and longevity — just not so much that you overcharge it. As previously mentioned, that will lead to all kinds of other problems.

Lithium-ion battery vs lead acid

The use of Li-ion batteries has revolutionised the way we use and store energy, providing a more efficient and reliable option compared to traditional lead-acid batteries. But many businesses still swear by their lead-acid cells. How do the two compare?

  • Firstly, Li-ion batteries have a higher energy density than lead acid cells. This means they can store more energy in a smaller space.
  • Secondly, they have a longer lifespan, can be recharged more times, and don't suffer from the same memory effect that lead-acid batteries do.
  • Finally, lithium-ion batteries are lighter and more compact than lead-acid batteries, which makes them ideal for portable devices like smartphones and laptops.

Despite their widespread use, Li-ion batteries still face challenges such as safety concerns, and their environmental impact has both positives and negatives. Ongoing research is focused on improving their performance and increasing their sustainability.

They are typically more expensive than lead acid batteries, both to buy up front and to install. You’ll want to invest in specialist storage solutions to protect your people and your workspace from the risk of fire or an exploding battery (and to likewise protect your vulnerable batteries from external factors that could damage them, such as heat).

They also need to be disposed of responsibly, although this is also true of lead acid types.

Overall, if your operations can afford them, Li-ion batteries are usually the superior choice for most applications due to their higher energy density, longer lifespan, and smaller size.

Related read: What Are the Advantages and Disadvantages of Lithium-Ion Batteries? 

Could lithium-ion improve your operations?

You might be using Li-ion batteries already, or you might be considering them for the first time. Whichever side of the separator you sit on, lithium-ion technology has the potential to help you do more for less. We hope this article helps you to feel more confident about lithium-ion technology and to use Li-ion batteries more responsibly across your operations. 

To download your copy of our four-step risk assessment checklist for lithium-ion batteries, click here.