Blog

Welcome to the second installment of the Coffee Break series, where I share topics that have caught my attention and insights I find worth passing along.
In this post, I’d like to take a closer look at batteries, an indispensable part of our everyday lives.
 
 

Lithium-ion batteries have become commonplace, but so have fire incidents

 
In recent years, news reports about fires caused by lithium-ion batteries in devices such as smartphones and portable power banks have become increasingly common.
Hearing that the batteries inside products we use every day can potentially catch fire naturally makes many people uneasy.
One of the primary causes of these incidents is thermal runaway, a phenomenon in which a battery rapidly generates heat and spirals out of control. Common triggers include:

• Internal damage caused by strong impacts
• Use or storage in high-temperature environments
• Improper charging practices

On the other hand, we rarely hear about conventional dry cell batteries causing fires.
Why is there such a difference?
 
 

What exactly is a lithium-ion battery?

 
Most people are familiar with the term lithium-ion battery, but surprisingly few understand how it actually works.
Lithium is a chemical element belonging to the alkali metal group, represented by the symbol Li. An ion is an atom that has gained or lost electrons and therefore carries an electric charge.
Although this may sound somewhat technical, a lithium-ion battery can be explained quite simply as: ‘A battery that stores and releases energy by allowing lithium ions to move back and forth between a positive electrode and a negative electrode’.
This mechanism enables lithium-ion batteries to achieve a high energy density, which is why they are widely used in smartphones, laptops, portable power banks, and many other electronic devices.
 
 

The role of liquid electrolyte in fire risk

 
In today’s lithium-ion batteries, lithium ions move through a substance known as an electrolyte. In most cases, this electrolyte is a liquid made from flammable organic solvents. While these materials help lithium-ion batteries achieve high performance, they can also pose safety risks under certain conditions.
For example, the following situations can increase the likelihood of a battery overheating or catching fire:

• Severe physical impact
• Damage to internal components caused by aging or wear
• Internal short circuits

When any of these occur, the battery may generate heat rapidly, potentially leading to ignition.
 
 

How are they different from dry cell batteries?

 
So, what makes dry cell batteries different?
Like lithium-ion batteries, dry cell batteries also contain electrolyte. However, the electrolyte used in most dry cell batteries is typically water-based. As a result, even when exposed to heat, it does not burn the way flammable organic solvents do.
Of course, dry cell batteries can still generate heat or even rupture if they are short-circuited. However, they are generally considered to have a lower risk of catching fire than lithium-ion batteries.
 
This naturally raises an important question: Why not use a water-based electrolyte in lithium-ion batteries as well?
 
The answer lies in the way lithium-ion batteries work.
Lithium-ion batteries are rechargeable batteries designed to be charged and discharged repeatedly. If a water-based electrolyte were used, the water could break down through electrolysis during charging, making it difficult to maintain the battery’s performance and efficiency.
For this reason, organic solvent-based electrolyte remains the standard choice in most lithium-ion batteries today.
 
 

All-solid-state batteries: A promising next generation technology

 
To address these challenges, all-solid-state batteries have attracted considerable attention in recent years.
As the name suggests, all-solid-state batteries replace the liquid electrolyte used in conventional lithium-ion batteries with a solid electrolyte.
In fact, technology itself is not entirely new. Researchers around the world have been exploring and developing all-solid-state batteries for over a decade. However, significant technical challenges have made commercialization difficult, and large-scale production has taken longer than many initially expected.
Some of the key benefits expected from all-solid-state batteries include:

• Longer driving ranges for electric vehicles (EVs)
• Faster charging times
• Reduced risk of fire
• Longer battery life

These advantages have the potential to enhance not only electric vehicles but also many of the devices we rely on every day, including smartphones and laptops.

However, the promise of all-solid-state batteries extends beyond improving the performance of consumer electronics. For decades, experts in the energy sector have pointed out that storing electricity is often more challenging than generating it. Advances in battery technology therefore play a critical role in shaping the future of energy use and management.

The importance of energy storage was highlighted in 2019, when Japanese researcher Akira Yoshino was awarded the Nobel Prize in Chemistry for his contributions to the development of lithium-ion batteries.
Today, lithium-ion batteries are widely recognized as one of the foundational technologies underpinning modern society.
If all-solid-state batteries achieve widespread adoption in the future, they could help create a world that is not only safer and more convenient, but also more energy-efficient.
 
As battery technology continues to evolve, it will be fascinating to see how these innovations transform the way we live and use energy.