In a world where Li-ion batteries are powering our cellphone, laptops, power tools and electric cars, recycling the overwhelming amount of dead batteries threatening our landfills is surely important. However, Recycling is only but the third “R” and should be considered a last resort for when Reducing and Reusing have failed. Ideally, these batteries, which contain valuable metals, would last forever and would be reused repeatedly avoiding both the need for further mining and avoiding piling in landfills. But like all good things, these batteries cannot last forever; with usage, their capacity to store energy fades. Understanding the failure mechanisms of Li-ion batteries allows us, as users, to extent their lifetime thus protecting our investments as well as the planet.
If you are considering a large investment, whether it is an electric vehicle or an expensive laptop, you would want to make the most out of your battery’s lifetime. A better understand of what kills Li-ion batteries is not only beneficial to avert the impending e-waste crisis, it is also to the advantage of the user that the battery maintains its health for as long as possible to delay the need to replace the whole car, laptop, cellphone, etc. – Reduce.
This also gives rise to a larger second-use market. If after five or more years of driving, the battery pack in an electric car is at a sufficient state of health to allow the car to be used for another ten years, more affordable used electric vehicles would be accessible on the market. This also applies to mobile electronics devices where the battery performance fade seems to be the main concern when buying a used device – Reuse.
The question now remains, how to make these batteries last longer? The conditions under which a Li-ion battery operates. High voltage storage, charge/discharge rate and temperature are critical factors to its longevity. Often, we do not need to heavily exert our batteries, but lack the understanding of the failure mechanisms that are silently deteriorating them. If charging a battery to 70% is sufficient for regular usage, then it is best to limit the battery charge to 70%. Parasitic reactions that occur between the electrode and the electrolyte in the battery are accelerated at high voltage – that is, when the battery is charged closer to 100%. Fast charging, albeit convenient, also degrades the battery faster. Whenever possible, using a slower charger will prevent the degradation of the electrodes in the Li-ion batteries and appreciably increase their lifetime. Lastly, operating a battery at a moderate temperature is also important for its health. The thermal parameter is often outside of the control of the user, but it is an important parameter nonetheless as it can accelerate the kinetics of the reactions that degrade the battery.
We must recognize that, despite modern advances in technology and science, recycling Li-ion batteries is currently challenging. Thankfully, the easiest waste to recycle is always the waste that is not created. Researchers and scientists all over the world are working on developing state of the art Li-ion batteries that are more robust and last longer, but let us not underestimate our role as informed users to contribute to resolving this problem.
