Lithium Ion Battery 

By on

Over recent years the Lithium Ion battery has become popular in applications requiring high power densities with small weight and footprint.  Today Lithium Ion batteries are commonly found in mobile phones, portable electronics, power tools, electrically operated vehicles and military applications. In addition to high power densities, Lithium Ion batteries are chargeable and have no memory effect.

litiumIonBattery
Charge/discharge mechanism of a Lithium Ion battery
Image Source: http://batteryuniversity.com
Developed in the early 1970's  at Birmingham University in the UK, Lithium Ion batteries consist of a Lithium Metal Oxide positive electrode (cathode), carbon negative electrode (anode) and electrolyte of a lithium salt organic solution. During the discharge process, Lithium Ions move from the negative to the positive electrode, via the external circuit.   During the charging the process is reversed by applying an over voltage.

The Lithium Metal Oxide cathode is constructed using various metals with resulting differences in performance:

  • Lithium Cobalt Oxide - high energy density, some safety issues
  • Lithium Iron Phosphate - low energy density, long life, safe
  • Lithium Manganese Oxide - low energy density, long life, safe
  • Lithium Nickel Manganese Cobalt Oxide - low energy density, long life, safe
  • Lithium Nickel Cobalt Aluminum Oxide - special applications
  • Lithium Titanate - special applications

Advantages of Lithium Ion Batteries:

  • variety of shapes and sizes
  • lighter than other battery types
  • no memory effect
  • low self discharge rate (5-10% per month)
  • low maintenance

Disadvantages of Lithium Ion Batteries:

  • capacity diminishes with charging
  • internal resistance increases with charging
  • capacity loss increases at high temperatures
  • capacity loss on ageing

As a note of caution, there is the possibility of thermal runaway if a Lithium Ion battery is over charged.  Where this is a risk, internal fail safe circuits to shut battery down are incorporated.

Typical Battery Characteristics

Lithium Cobalt
LiCoO2
Lithium Manganese
LiMn2O4
Lithium Iron Phosphate
LiFePO4
Lithium Manganese Cobalt Oxide
LiNiMnCoO2
Lithium Nickel Cobalt Aluminum Oxide
LiNiCoAlO2
Lithium Titanate
Li4Ti5O12
  LCO LMO LFP NMC NCA LTO
Voltage 3.60V 3.80V 3.30V 3.60/3.70V   2.4V
Charge Limit 4.20V 4.20V 3.60V 4.20V    
Cycle Life 500–1,000 500–1,000 1,000–2,000 1,000–2,000    
Operating Temperature Average Average Good Good    

Specific Energy

150–190Wh/kg

100–135Wh/kg

90–120Wh/kg

140-180Wh/kg

   
Safety Average. Needs protection circuit.
Average. Needs protection circuit.
Very safe. Needs voltage protection. Safe. Needs protection circuit.    
Thermal. Runaway 150°C
(302°F)
250°C
(482°F)
270°C
(518°F)
210°C
(410°F)
   
In Use Since 1994 1996 1999 2003    
Application very high specific energy, limited power; cell phones, laptops high power, good to high specific energy; power tools, medical high power, average
specific energy, elevated self-discharge
very high specific energy, high power; tools, medical
electric powertrain and grid storage
electric powertrain and grid storage

 

Storage

Capacity loss due to storage is a problem with Lithium Ion batteries.  This loss is dependent on the charge state, storage time and storage temperature.  The normal recommendation is to store batteries approximately 40% charged.  If stored for one year at 40% charge and 0oC, the recoverable capacity at the end of this period would be around 98%.  As storage temperature increases to 60oC, the recoverable charge will decrease typically to around  75%.  If the batteries were fully charged the recoverable charge would be 94% and 60%. 

 

If anyone has any tips or other information to add, just leave a comment and I’ll incorporate it into the article.



Steven McFadyen's avatar Steven McFadyen

Steven has over twenty five years experience working on some of the largest construction projects. He has a deep technical understanding of electrical engineering and is keen to share this knowledge. About the author

myElectrical Engineering

comments powered by Disqus



Railway Electrification Voltages

This post is quick introduction and overview to different railway electrification voltages used in answer to a question sent in via email. While there...

DC Motor Operation

Coils of wire on the rotor carry a d.c. current which generates a magnetic field. A stator magnetic field is created using either permanent magnets or...

Our internet address and Vanity URLs

Visitors who like to type web address rather then click menus may be interested in how our URL structure works.

How to measure power supply quality

If your are ever called out to troubleshoot something on your electrical system, one of the first things consider is the supply voltage. You want to ensure...

myElectrical - Cable Sizing Tool Upgrade

Our IEE cable sizing was wrote a few years ago and had become rough around the edges. I thought it was time to give the tool a service. Unfortunately when...

Why use catalogues

I'm a fan of using manufacturers catalogues. There are two main reasons for this. Firstly, if your involved in the purchase of equipment, you will likely...

The dc resistance of conductors

This is the first of two posts on the resistance of conductors. In the next post I will look at the ac resistance, including skin effect and we deal with...

UPS Sizing - Rules of Thumb

It wasn't so long ago I was telling someone that I don't use rules of thumb as most things are easily calculated anyhow.   As it turns out I last week...

9 power supply issues solved by using a UPS

Installation of a UPS can help in reducing problems due to issues with the power supply.  A lot of people relate this to nine key issues.  Depending on...

Network Theory – Introduction and Review

In electrical engineering, Network Theory is the study of how to solve circuit problems. By analyzing circuits, the engineer looks to determine the various...

Have some knowledge to share

If you have some expert knowledge or experience, why not consider sharing this with our community.  

By writing an electrical note, you will be educating our users and at the same time promoting your expertise within the engineering community.

To get started and understand our policy, you can read our How to Write an Electrical Note