We’ve all been there. You are camped out on your couch with your laptop, Facebooking (yes, this is actually an accepted verb now!) with your friends and family when you get the low battery signal, warning you that you have 20 minutes of power left. Or you are on a long plane flight, trying to watch a movie to pass the time, and are three quarters of the way through an exciting action thriller when you realize the low-battery signal on your tablet came on awhile ago and you won’t get to see the end of your movie. How does the conflict get resolved? Does the villain get caught? Now you are going to have to wait to find out. Frustrating indeed!
Today’s society is very mobile and with this desire for mobility comes an increasing need for portable energy sources. Batteries allow us to generate electricity when and where we need it. As our need for portable energy continues to grow, so too does the demand for better battery technology. Some devices such as portable electronics and power tools use very small batteries and others, such as hybrid vehicles, use much larger batteries. The individual requirements (potential, capacity, discharge rate, etc.) vary with the intended use.
Disposable batteries provide safe, inexpensive power for all your electrical devices which cannot be tied down with a power cord. However, the chemical reaction that takes place inside the battery has a limited lifetime and cannot be reversed which means the battery cannot be recharged and reused. As the chemicals are depleted, the battery’s power dwindles until it eventually fails. Therefore, their ultimate flaw…they are disposable.
In response to the limitations of disposable batteries, rechargeable batteries were developed. Rechargeable batteries have gone through a number of design iterations to address power output, safety, cost and environmental impact and the lithium-ion battery design has become the most popular for its ability to address those considerations.
Challenges of Lithium-Ion Battery Technology
Lithium-ion batteries have widely replaced nickel metal-hydride batteries in a number of applications. They possess a high energy density which allows them to produce the same or greater output voltage as a lead acid battery, but in a smaller, lighter weight package. The batteries have no significant memory effects and lose minimal charge when not in use. With proper handling and use, lithium ion batteries will last several years before needing replacement.
Understanding battery failures requires analysis of the three main battery components (cathode, anode and electrolyte), individually and how they interact together as a system. The processes that a lithium-ion battery undergoes are complex, which requires a variety of instruments and technologies to properly investigate. The approach described in the presentation I mentioned at the start of this post used ion chromatography (Thermo Scientific Dionex ICS-5000+ RFIC HPIC system), ion chromatography-high resolution mass spectrometry (Thermo Scientific Q Exactive Plus Mass Spectrometer) and ion chromatography-inductively coupled plasma mass spectrometry (Thermo Scientific iCAP Q) to identify and quantify a handful of degradation products in lithium-ion batteries that had undergone varying numbers of charge/discharge cycles. The results are quite interesting. I encourage you to check out the 26-min presentation below. Click the Play button to start the video.