Lithium battery general information
Introduction
Lithium batteries are considered a fairly new technology that can provide significant electrical energy in a relatively small package. The term "lithium battery" is used as a general phrase that refers to batteries which contain some form of lithium. There are two types of lithium batteries, lithium metal and lithium ion.
Lithium Metal
Lithium metal batteries are a primary (non-rechargeable) battery that uses lithium metal or lithium alloys as the primary component of its anode and manganese dioxide as a component for the cathode. These batteries are typically found in smaller electronic devices with replaceable batteries.
Lithium Ion
Lithium ion (Li-ion) batteries are a secondary (rechargeable) battery that uses lithium ions as the primary component of its electrolyte. Li-ion batteries can use several different materials as electrodes. The most common combination is that of lithium cobalt oxide (cathode) and graphite (anode). These batteries are typically found in electronic devices that are rechargeable.
Battery vs. Cell
Most people use the word "battery" as a broad term that encompasses both batteries and cells. It’s important to know the regulations refer to them separately as batteries or cells because there are different requirements for each one.
A cell is a single electrochemical unit that has two electrodes (one positive and one negative), one electrolyte, one separator, and one electric circuit. Typically, these can include button cell, AA, AAA, C, and D.
A battery is made up of two or more cells that are connected to obtain the desired voltage. Typically, these can include car and laptop batteries.
Caution: There are batteries that are designed to look like cells. If you are unsure if you have a battery or a cell, contact the manufacturer for clarification.
Lithium Battery Rating
Since lithium metal batteries use actual lithium metal or alloy to help generate its energy and lithium ion uses a chemical reaction without lithium metal or allow to help generate its energy, they are rated different. Lithium metal batteries are rated by the amount of lithium metal or alloy they contain by weight in grams. Lithium ion batteries are rated by watt-hours.
Lithium Metal Content
The amount of lithium metal a lithium metal battery contains is how the battery is rated. Knowing the lithium metal content of the battery that you are shipping is important because it will help to determine how the battery must be packaged, marked, and labeled.
Often times the lithium content for lithium metal batteries is not listed on the battery itself. If the lithium content is not listed on the battery, how do you find out how much lithium content your battery contains?
One way to determine the lithium content would be to check any product paperwork you may have, such as the Safety Data Sheet (SDS), specification information, or the test summary report that may be provided with the product.
Another way would be to calculate the lithium content yourself using the equation: Ah x 0.3 x number of cells = lithium content (Ampere-hour x 0.3 (It requires about 0.3 grams of lithium metal to produce 1 Ampere hour of power) x the number of cells the battery has = lithium content in grams).
Example: A battery that has 2.5 Ah and 6 cells would have a lithium metal content of 4.5 grams (2.5 x 0.3 x 6 = 4.5).
Watt-Hour
Watt-hours are used to express how much energy (measured in watts) a lithium ion battery can use in one hour. Knowing the watt-hour of the battery that you are shipping is important because it will help to determine how the battery must be packaged, marked, and labeled.
Newer lithium ion batteries are required to have the watt-hour marked on the battery, so finding the watt-hour should be as simple as looking on the battery itself. However, how do you find the watt-hour on an older battery or on a newer battery where the watt-hour is rubbed off or missing?
One way to determine the watt-hour would be to check any product paperwork you may have, such as the Safety Data Sheet (SDS), specification information, or the test summary report that may be provided with the product.
Another way would be to calculate the watt-hour yourself using the equation: Ah x V = Wh (Ampere-hour x Volt = Watt-hour). Since most batteries already have the ampere-hours and volts marked on the battery, this formula should be easy to calculate.
Example: A battery that has 50 Ah and 12 V would have 600 Wh (50 x 12 = 600).