Combine outer and inner packaging material to safely ship lithium-ion batteries
In a previous blog, we answered the question ‘what packaging should I use to ship lithium-ion batteries?’ To summarize: this cannot be described in a general manner since there are three main factors that determine your lithium-ion battery packaging. There is, however, one requirement that is common and ubiquitous — regardless of the mode of transport, weight, and state of your LiB. In this blog, we describe this requirement. And how to meet it, of course. Hint: it has something to do with combining inner and outer packaging.
The danger of lithium-ion batteries
One of the greatest dangers of lithium-ion batteries is that they can catch fire due to a short circuit. In case of a short circuit, the battery heats up from its own energy content and eventually catches fire. More specifically, a short circuit is a result of the battery terminals coming into contact with other batteries, metal objects, or conductive surfaces. Terminals can also reorient with short circuits as a result.
One common UN packaging requirement to ship lithium-ion batteries therefore is that your battery has to be protected from short circuit. You can do so by combining the right outer and inner packaging. In this process, the inner packaging is most important, since it can prevent batteries from shifting or coming into contact with each other.
Inner packaging to the rescue
According to The International Air Transport Association’s (IATA) Lithium Battery Guidance Document, there are several inner packaging protections you can have in place to prevent your battery from short circuit:
- Separating your lithium-ion batteries by containing them in fully enclosed inner packagings made of non-conductive material, such as a plastic bags;
- Preventing battery movement inside the packaging — and therefore shifting, which could loosen terminal caps or reorient the terminals to produce short circuits — by:
- Cushioning the battery
- Installing fixation points that bolt the battery to the base of the box or crate
- Loading securing straps that attach the battery to a pallet
- Applying wooden attachments to the base and lid of the box or crate to create a fixation of the battery
- Ensuring exposed terminals or connectors are protected with non-conductive caps, non-conductive tape, or by other appropriate means.
Despite short circuit protection measurements, a battery can still catch fire. To deal with this worst case scenario as compliantly as possible, your packaging should be designed to limit the effects of fire. When we look at inner packaging, these protections mostly come in the form of fire suppressing material.
The topic of developing fire suppressing packaging is especially interesting because of the detailed fire and load test that’s involved. One of our next blog posts will cover that topic. If you want to get updated when new articles — like the one about the fire and load test — get published, please subscribe to our blog updates in the top right corner of this page.
Let’s now look at an example of combined inner and outer packaging for LiBs.
Example of combining inner and outer packaging for lithium-ion batteries
As we described in a previous blog, damaged batteries add very tough, unique requirements to fire safety during transport. An example of how to deal with these strict requirements is a damaged lithium-ion battery packaging we developed for a customer. We created a sophisticated steel container with a built in fire suppression system, liquid spill tray, and fixation points. The inner packaging is made from steel and Kevlar aramid. The intricate internal design allows pressure release without any flame penetration. Even if the battery were to ignite in the box, the temperature on the surface will stay at an acceptable level.
Figure 1: the box is Dangerous Goods Packing Group I certified, with the possibility to load 1,400 kg
You can also read this customer case to see how we helped a customer with organizing the shipment and return of lithium ion batteries to various distribution points on a global level. A main requirement from the customer was to be provided with safe distribution of their replacement batteries, but also the ability to switch the old battery with the replacement and send it back in the same box.
Take a look to see how we reduced this customer's cost of logistics with an efficient and compliant Lithium Ion Battery packaging solution — download the free case here:
Published by Guilherme Ueda on Sep 7, 2017, 8:28:47 AM