What is a Li‑ion Battery?

Li‑ion batteries are rechargeable energy storage devices where lithium ions shuttle between electrodes to deliver power, and they form the backbone of modern electronics and portable power solutions. Global lithium‑ion battery capacity reached nearly 2,000 GWh in 2023. 

Understanding what a Li-ion battery is helps you choose the right chemistry, form factor, and lifecycle for your needs. At EBL, we guide you through key features and performance factors to ensure reliable power and longer-lasting battery life.

Table of Contents

• Who Invented the Lithium-Ion Battery and When?
  
• What Does a Lithium-Ion Battery Look Like?
• Types of Lithium-Ion Batteries
• Lithium-Ion Battery Sizes
• Weight of a Lithium-Ion Battery
• How Long Does a Lithium-Ion Battery Last?
• Li‑ion Battery Smell: What Does It Indicate?
• What Devices Have Lithium-Ion Batteries?
• Sustainability & Recycling
• FAQ

Who Invented the Lithium-Ion Battery and When?

The abbreviation for lithium-ion battery is Li‑ion; its electrodes and long-cycle life across applications from portable electronics to electric vehicles (reference: The Clean Energy Institute). 

Early academic interest exploded in the 1970s, with researchers publishing a surge of papers on rechargeable cells by the end of the decade.

In 1972, M. Stanley Whittingham demonstrated the first working prototype at Exxon Research, using a titanium disulfide cathode and a lithium‑aluminum anode to enable reversible intercalation.

Exxon briefly manufactured small volumes and showcased Li‑ion coin cells at a 1977 electric‑vehicle exhibition in Chicago, yet safety concerns stalled wider adoption. 

The real leap came in 1980 when John B. Goodenough introduced lithium cobalt oxide cathodes, boosting energy density and defining the lithium ion battery definition engineers still use today.

Akira Yoshino’s 1985 patent replaced reactive lithium metal with a stable carbon‑based anode, making what is a lithium-ion battery truly viable for consumers.

Two years later, Sony and Asahi Kasei launched the first commercial lithium‑ion cells in June 1991, marking the official birth of the abbreviation for lithium-ion battery—Li‑ion—in everyday electronics.

Goodenough’s Japan Prize in 2001 further underscores the impact of his LiCoO₂ discovery on modern energy storage.

This milestone ushered in a new era of portable power, from laptops to power tools, and set the stage for today’s EV and solar applications. These batteries have seen volumetric energy density triple while cost plummeted tenfold since commercialization.

For their pioneering work—from intercalation electrodes to stable cathode and anode materials—Whittingham, Goodenough, and Yoshino were awarded the 2019 Nobel Prize in Chemistry, highlighting how these breakthroughs underpin today’s Li‑ion battery landscape.

What Does a Lithium-Ion Battery Look Like?

Visual anatomy (infographic)

A typical Li‑ion cell comprises a metal casing, current collectors, electrode jelly rolls, a separator, and an electrolyte reservoir. 

The metal shell—either cylindrical steel or prismatic aluminum—houses the jelly roll, where porous carbon anode and metal oxide cathode layers wind around a separator membrane.

Cell markings & identification

Every Li‑ion cell bears a data plate listing model number, voltage, capacity, and manufacturing codes—key for verifying genuine performance. 

IEC 61960 nomenclature codes printed on cylindrical cells—e.g., 18650, where ‘18’ indicates diameter in mm and ‘650’ length in tenths of mm—help you recognize size and format. 

Look for UL or CE marks and UN 3480/UN 3481 labels to confirm safety testing and shipping compliance.

Types of Lithium-Ion Batteries

Not all Li-ion batteries are created equal—understanding their shapes and chemistries can help you pick the perfect match for your needs.

Cylindrical vs. prismatic vs. pouch

Li-ion batteries come in three main shapes: cylindrical, prismatic, and pouch.

• Cylindrical cells (like the popular 18650 and 21700 models) are shaped like small cans. They’re rugged, efficient at cooling, and often used in power tools, e-bikes, and even Tesla vehicles. If you imagine batteries stacked like soda cans inside a device, you’re picturing cylindrical cells.
• Prismatic cells have a rectangular or boxy shape. They are packed tightly for space efficiency, making them a favorite for laptops, smartphones, and energy storage systems. Think of them as little power bricks—organized, compact, and powerful.
• Pouch cells are ultra-thin and flexible, wrapped in lightweight foil. You’ll find them in phones, tablets, and drones where saving space and weight matters most. However, they require more careful handling to prevent swelling.

Choosing between these depends largely on your application needs: cylindrical for durability, prismatic for space savings, and pouch for ultra-lightweight designs.

Now let's get into the inner chemistry of these batteries: NMC, LFP, and NCA variants.

NMC, LFP, NCA chemistry variants

Behind every lithium-ion battery shape lies a powerful chemical secret.

• NMC (Nickel Manganese Cobalt Oxide) is the jack-of-all-trades chemistry. It's widely used in EVs and portable electronics because it balances high energy density with decent lifespan and safety. When you think about long drives in an electric car or powering a cordless drill, chances are it’s an NMC battery at work.
  
  
• LFP (Lithium Iron Phosphate) prioritizes safety, longevity, and thermal stability. LFP batteries don't pack as much energy per pound, but they last significantly longer and are much less prone to overheating. Perfect for solar storage, portable power stations, and applications where reliability over years is critical. At EBL, many of our solar generators use advanced LFP cells for this reason!
  
  
• NCA (Nickel Cobalt Aluminum Oxide) offers the highest energy density among common Li-ion chemistries. It’s typically found in premium electric vehicles and aerospace-grade applications where weight-saving and maximum range are top priorities.
  

Each chemistry comes with trade-offs between cost, weight, safety, and cycle life. When choosing an EBL Li-ion battery, knowing whether you need rugged durability, top-end performance, or rock-solid reliability will help you pick the right type.

Lithium-Ion Battery Sizes

Size isn’t just about fitting into a device — it impacts how much energy you can store, how fast you can charge, and even the safety profile of the battery. When you're choosing a Li-ion battery for your specific need, dimensions play a bigger role than you might think.

Standard form factors (18650, 21700, 14500)

Let’s start with the heavy hitters: standardized Li-ion sizes that dominate the market.

• 18650: Possibly the most famous lithium-ion battery. The "18" refers to 18mm in diameter, and "650" to 65.0mm in length. It's widely used in laptops, flashlights, and power tools. Tesla famously used thousands of 18650 cells to power their early Model S vehicles. With about 2600–3500mAh capacity per cell, it offers a balanced combo of size, energy, and reliability.
  
  
• 21700: Slightly bigger and newer than the 18650, with 21mm diameter and 70mm length. Why the upgrade? Higher energy density and longer run times. These batteries are becoming the norm for newer EVs and high-capacity power stations. If you're shopping for what is li ion battery for modern devices, expect to see more 21700 models.
  
  
• 14500: Smaller and lighter, similar in size to a standard AA battery (14mm x 50mm). It’s commonly found in compact flashlights and wireless gadgets. Despite its small size, it still delivers a serious punch compared to traditional alkaline batteries.

Each form factor has its strengths: 18650 for versatility, 21700 for high performance, and 14500 for space-saving designs. Choosing the right one often comes down to matching size with the desired energy and application.

Custom pack dimensions

Standard batteries are great, but sometimes you need a power solution as unique as your project. That’s where custom battery packs come into play.

Custom Li-ion packs are often designed for:

• Medical equipment
• Specialized drones
• Industrial IoT devices
• Solar energy storage systems

Custom packs can combine cylindrical, prismatic, or pouch cells to meet exact voltage, capacity, and space requirements. You might see them wired in series for higher voltage (like 24V, 36V, 48V packs) or in parallel to boost capacity without increasing voltage.

Whether it’s a neat 18650 pack for your flashlight or a rugged custom battery for off-grid adventures, knowing your lithium-ion battery sizes is a crucial step in getting reliable power.

Weight of a Lithium-Ion Battery

When considering applications like portable electronics, drones, or solar power banks, understanding the weight of a lithium-ion battery can make or break your decision. After all, nobody wants to carry a "portable" device that feels like a brick!

When exploring a Li-ion battery for lightweight designs, two things matter: energy-to-weight ratio and chemistry differences.

Wh/kg Ratio

One of the best ways to measure a battery’s weight efficiency is the watt-hour per kilogram (Wh/kg) ratio.

• Wh (Watt-hours) measures how much energy a battery stores.
• Kg (kilogram) measures how heavy the battery is.

In simple terms, the higher the Wh/kg, the more powerful and lightweight the battery.

Current commercial lithium-ion batteries typically offer:

• 150–250 Wh/kg for consumer electronics.
• 250–300 Wh/kg for electric vehicles and advanced storage.
• 300+ Wh/kg for experimental next-gen cells (still rare commercially).

For example, if you have a 18650 cell weighing about 45g with a 12Wh capacity, the rough energy density is 267 Wh/kg—pretty impressive for something smaller than your thumb.

When comparing what is lithium-ion batteries across different products, keep an eye on the Wh/kg figure if weight and portability are your top concerns.

Chemistry‑Based Weight Differences

Not all lithium-ion batteries are cut from the same chemical cloth—different chemistries mean different weights for the same amount of power.

• NMC (Nickel Manganese Cobalt Oxide) batteries are popular for electric cars and smartphones because they offer a high Wh/kg (about 200–260 Wh/kg), striking a sweet spot between weight, energy, and longevity.
  
  
• LFP (Lithium Iron Phosphate) batteries, like those used in many EBL solar products, are heavier (90–160 Wh/kg) but trade a little extra weight for unbeatable safety, cycle life, and temperature resilience. Perfect when you need something tough and worry-free.
• NCA (Nickel Cobalt Aluminum Oxide) batteries tend to be the lightest and most energy-dense (up to 300 Wh/kg). They’re favored in high-performance EVs like Tesla’s Model S and Model 3 for achieving longer driving ranges with minimal added weight.

In short:

• Need ultra-lightweight? Go for NCA.
• Need durable and safe? Choose LFP.
• Need balanced performance? NMC wins.

This subtle dance between chemistry and weight shows why lithium-ion batteries involve more than just voltage and size. It wrapped up in how each formula supports your actual needs—power, lifespan, safety, or portability.

How Long Does a Lithium-Ion Battery Last?

Once you’ve picked the right size and weight, another critical question comes up: how long does a lithium-ion battery last? No one wants a battery that gives up halfway through its expected life.

Battery longevity isn’t just luck; it’s shaped by how you use and care for your battery. Let’s break it down.

Cycle Life Factors (DoD, Charge Rate)

Cycle life refers to how many complete charge and discharge cycles a lithium-ion battery can handle before its capacity falls below 80% of its original level. But "one cycle" isn’t always draining 100%—partial usage counts too.

Key factors that impact cycle life include:

• Depth of Discharge (DoD):
  The deeper you drain a battery each time, the fewer cycles it will last.
  
  
• 100% DoD (full drain) = Shorter life (about 500–800 cycles)
• 30% DoD (partial drain) = Much longer life (up to 5,000 cycles)

If you recharge when your battery hits 70% instead of waiting for it to die completely, you can double or triple its lifespan. It’s like eating when you’re slightly hungry instead of starving—your "battery health" stays better longer!

• Charge Rate (C-Rate):
  Fast-charging is convenient but stressful for batteries. Charging at 1C (full charge in 1 hour) is fine for daily use, but ultra-fast rates (like 2C or higher) heat up cells and wear them out faster. Stick to moderate charge rates when possible to maximize your battery’s useful life.
  

Quick stat: According to Battery University, reducing the charge voltage from 4.2V to 4.1V can extend a battery’s cycle life by over 50%, although it slightly reduces total capacity.

Calendar Life & Storage Conditions

Calendar life measures how long a lithium-ion battery lasts over time, even if you don’t use it much. Just like fresh produce, batteries "age" naturally due to chemical reactions inside the cells, even when idle.

Here’s what impacts calendar life:

• Temperature:
  Storing or operating batteries in high heat accelerates chemical breakdown. Keeping your batteries at around 20–25°C (68–77°F) prolongs life.
  
  
• State of Charge During Storage:
  Batteries stored fully charged (100%) or fully discharged (0%) age faster. Ideally, store them at around 40–60% charge.
  It’s like letting your muscles rest slightly flexed, not stretched to extremes.
  
  
• Environmental Humidity:
  Excess moisture can seep into battery packs and cause corrosion or short circuits. Always store in dry, ventilated areas.

Real-world figures? A high-quality lithium-ion battery can retain 70–80% of its original capacity after 5–10 years with proper care, even if lightly used.

If you’re using EBL Li-ion batteries in your devices or power stations, following these tips ensures you’ll get the maximum performance over time. 

Plus, our advanced Battery Management Systems (BMS) further optimize life expectancy by monitoring temperature, charge rates, and voltage balancing.

Li‑ion Battery Smell: What Does It Indicate?

If you’ve ever caught a whiff of something fruity, sweet, or oddly chemical near your device, it might not be your imagination—it could be your lithium-ion battery signaling distress. 

Understanding what a Li-ion battery smells like and its implications is crucial for safety and device longevity.

Causes (Electrolyte Breakdown, Venting)

Lithium-ion batteries contain a flammable electrolyte solution, typically comprising organic solvents like ethylene carbonate and dimethyl carbonate. Under normal conditions, this electrolyte is safely sealed within the battery. However, certain factors can cause this seal to break:

• Overcharging or overheating: Excessive charging or exposure to high temperatures can cause the electrolyte to decompose, producing gases.
• Physical damage: Dropping or puncturing the battery can breach its casing, leading to leakage.
• Manufacturing defects: Poorly made batteries might have weak seals or internal flaws that lead to leakage over time.

When the electrolyte leaks, it emits a distinctive odor, often described as sweet, fruity, or solvent-like. This smell is a warning sign of potential battery failure, which could escalate to swelling, leakage, or even fire.

Safety Steps & Prevention

If you detect an unusual smell from your device, take the following precautions:

1. Power down: Immediately turn off the device and unplug it from any power source.
   
2. Isolate the device: Place it on a non-flammable surface away from combustible materials.
   
3. Do not attempt to use or charge: Avoid using or charging the device until it has been inspected or replaced.
   
4. Dispose of properly: Do not throw the battery in the trash. Instead, take it to a certified e-waste recycling center or follow local disposal regulations.

To prevent such issues:

• Use reputable brands: Purchase batteries and devices from trusted manufacturers.
• Avoid overcharging: Do not leave devices charging overnight or unattended.
• Store properly: Keep batteries in a cool, dry place away from direct sunlight.
• Inspect regularly: Check for signs of damage, swelling, or leakage.

Being proactive about battery care not only extends the life of your devices but also ensures your safety.

What Devices Have Lithium-Ion Batteries?

Lithium-ion batteries are the powerhouse behind countless devices we rely on daily. Their high energy density, lightweight design, and rechargeability make them ideal for a wide range of applications. Let's explore some common devices that utilize lithium-ion batteries.

Consumer Electronics

From the moment we wake up to the time we go to bed, lithium-ion batteries are integral to our daily routines. 

They power smartphones, laptops, tablets, and wearable devices like smartwatches and fitness trackers. 

These batteries offer the necessary energy to keep our devices running efficiently throughout the day without adding significant weight or bulk.

Power Tools & E‑Mobility

In the realm of power tools, lithium-ion batteries have revolutionized the industry. 

Cordless drills, saws, and other tools benefit from the high power output and long-lasting charge of these batteries, providing professionals and DIY enthusiasts with greater flexibility and mobility.

E-mobility solutions, including electric scooters, bicycles, and skateboards, also rely heavily on lithium-ion batteries. 

Their ability to deliver consistent power over extended periods makes them ideal for personal transportation devices, contributing to the growing trend of eco-friendly commuting options.

Solar & Portable Power Stations

Lithium-ion batteries play a crucial role in renewable energy storage. 

Solar power systems often incorporate these batteries to store energy collected during the day for use at night or during cloudy periods. 

Portable power stations, essential for camping trips, emergency backups, or off-grid living, utilize lithium-ion batteries to provide reliable and clean energy on the go.

Understanding the widespread use of lithium-ion batteries underscores their importance in modern technology. As we continue to seek efficient and sustainable energy solutions, these batteries will remain at the forefront of innovation.

Sustainability & Recycling

As lithium-ion batteries become integral to our daily lives, understanding their end-of-life management is crucial. Proper recycling not only conserves valuable materials but also mitigates environmental risks.

End-of-Life Recycling Options

When a lithium-ion battery reaches the end of its useful life, several recycling methods can recover its valuable components:

• Hydrometallurgical Processing: This method uses aqueous solutions to leach metals like lithium, cobalt, and nickel from shredded batteries. It's energy-efficient and can recover up to 95% of these metals.
  
  
• Pyrometallurgical Processing: Involves high-temperature smelting to extract metals. While effective, it consumes more energy and may emit greenhouse gases.
  
  
• Direct Recycling: An emerging technique that preserves the battery's cathode structure, allowing materials to be reused with minimal processing. This method shows promise in reducing energy consumption and preserving material integrity.

Companies like Redwood Materials are pioneering in this space, recovering over 95% of critical metals from used batteries and reintegrating them into new battery production.

Environmental Impact & Disposal Tips

Improper disposal of lithium-ion batteries poses significant environmental hazards:

• Toxic Leachate: Batteries in landfills can leak harmful substances like heavy metals into soil and groundwater.
• Fire Risks: Damaged or improperly disposed of batteries can ignite, leading to fires in waste facilities or collection trucks.

To minimize these risks:

• Do Not Trash: Never dispose of batteries in regular garbage or recycling bins.
• Use Designated Drop-Offs: Utilize local hazardous waste collection sites or retailer take-back programs.
• Store Safely: Keep used batteries in a cool, dry place, away from flammable materials, until they can be properly recycled.

By adhering to these practices, we can ensure that lithium-ion batteries are recycled responsibly, conserving resources and protecting our environment.

Empower Your Devices with EBL

Lithium-ion batteries have revolutionized how we power our lives, offering high energy density, rechargeability, and versatility across various applications. 

From smartphones to electric vehicles, their impact is undeniable. However, with great power comes the responsibility of proper usage, storage, and disposal to ensure safety and environmental sustainability.

At EBL, we are committed to providing high-quality, reliable, and eco-friendly battery solutions. Our range of rechargeable batteries and portable power stations are designed to meet your energy demands while minimizing environmental impact. 

By choosing EBL, you're not only investing in quality but also contributing to a greener future.

FAQ

Is a lithium battery the same as a Li-ion battery?

No, they are not the same. Lithium batteries are primary cells, meaning they are single-use and non-rechargeable. 

In contrast, lithium-ion (Li-ion) batteries are secondary cells, designed to be rechargeable and used multiple times. 

The key difference lies in their chemistry and intended usage.

What are the major advantages & disadvantages of a Li-ion battery?

Advantages:

• High energy density, allowing for longer usage between charges.
• Lightweight and compact, making them ideal for portable devices.
• Low self-discharge rate, retaining charge when not in use.
• No memory effect, so they don't require complete discharge before recharging.

Disadvantages:

• Sensitive to high temperatures, which can lead to degradation.
• Potential safety risks if damaged or improperly handled.
• Higher cost compared to some other battery types.
• Performance can degrade over time with repeated charging cycles.

Are Li-ion batteries rechargeable?

Yes, lithium-ion batteries are rechargeable. They are designed to undergo numerous charge and discharge cycles, making them suitable for devices that require frequent recharging. This rechargeability distinguishes them from primary single-use lithium batteries.

Can I bring lithium-ion batteries on a plane?

Yes, but with specific regulations:

• Carry-on baggage: You can bring devices with installed lithium-ion batteries. Spare (uninstalled) batteries must also be in carry-on luggage, not checked baggage.
• Watt-hour limits: Batteries with up to 100 Wh are allowed. For batteries between 101–160 Wh, airline approval is required, and you may carry up to two spares.
• Protection: Terminals should be protected to prevent short circuits.

Always check with your airline for specific policies before traveling.

What is the symbol for the lithium-ion?

The symbol for a lithium-ion battery typically includes the text "Li-ion" or "Li-ion battery" and may feature a battery icon with a lightning bolt or other indicators. Additionally, shipping labels for lithium-ion batteries often display a battery icon with flames to indicate flammability risks.