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Understanding Energy Storage: Batteries vs. Gasoline
A drop of gasoline, a match, and a battery all store energy. However, after each expends its energy, only the battery is recyclable. This is because, chemically speaking, a dead battery is not that different from a fresh one. Most of the batteries we use today take advantage of the fact that some metals like to release electrons and others like to accept them.
How Batteries Work
In a typical alkaline double-A battery, zinc metal reacts with hydroxide ions, changing into zinc oxide and releasing electrons at the negative terminal. The electrons travel through, say, a light bulb, and then return to the battery at the positive terminal, where they’re accepted by manganese dioxide. Different batteries use different combinations of metals and sometimes non-metals like graphite, but the basic idea is to use a pair of chemical reactions to generate a stream of electrons.
Rechargeable vs. Single-Use Batteries
Almost all batteries, even single-use batteries, are theoretically rechargeable. That’s because the metals and other chemicals are still right there. This is very different than in gasoline, where the liquid hydrocarbon molecules are converted to gases. You can’t convert exhaust back into gasoline, but, with some work, you can convert zinc oxide back to zinc. However, trying to recharge a single-use battery doesn’t just force these reactions to run in reverse. It also results in a bunch of side reactions that produce useless contaminants, reducing a battery’s capacity; and it could even damage the internal structure of the battery, leading to a loss of electrical contact and failure. Rechargeable batteries are engineered to avoid these issues.
How Lithium-Ion Batteries Work
Consider a lithium-ion battery. Both sides have an atomic-level structure that you can imagine as lots of docks. When the battery is powering something, the lithium “ships” give up their electrons to power the circuit, and then sail over to the other side of the battery, dock in an orderly, organized way, and meet up with their now-lower-energy electrons. When the battery is being charged, the opposite happens. Over the course of hundreds, sometimes thousands, of charge cycles, some of the lithium-ion ships sort of veer off course and engage in side reactions, producing stuff that increases the internal resistance of the battery, which in turn makes it lose efficiency and power until it inevitably dies.
Even when that happens, you can bring dead batteries back to life—whether they’re rechargeable or not— by recycling them. The heart of most battery recycling is a process called smelting, which is basically just melting the metallic parts. This drives off impurities, returning metals back to their initial, orderly state. Unfortunately, in many countries, you can’t just toss household batteries in with your regular recycling. You have to take them to a battery collection point or recycling center. The same goes for more complicated rechargeable batteries: you need to bring them to a collection point or send them back to the company you bought them from. It’s a pain, but absolutely worth the time and effort, because recycling batteries is critical.
The Importance of Battery Recycling
Not only does it prevent potentially toxic battery metals from leaking into the environment, it conserves scarce— and vital— resources. Earth has about 22 million tons of lithium—enough for about 2.5 billion EVs. That sounds like plenty, but it’s only 25% higher than the number of EVs experts believe it’ll take to reach net zero emissions by 2050, and that doesn’t even account for laptops, phones, and anything else that uses a lithium-ion battery. Currently, though, most lithium-ion batteries are not manufactured with recycling in mind. The designs are intricate and non-standard, and the components are held together by almost indestructible glues. So today, less than 5% of lithium-ion batteries are recycled.
Regulations and Battery Recycling
Regulations that clearly define who is responsible for a spent battery and what should happen to it can boost recycling dramatically. For example, lead-acid batteries are generally subject to stringent regulations and are recycled at much higher rates than lithium-ion batteries. Over the next century, we’ll need to recycle huge numbers of EV batteries, so scientists are working on making the battery recycling process cheaper and more environmentally friendly. Smelting uses a lot of energy and, depending on the type of battery, can release harmful by-products.
The Future of Battery Technology
In addition to regulations, industrial processes, and our own individual choices, battery tech will also continue to evolve. There are proof-of-concept batteries being developed that can convert physical force, ambient sound, and even urine into electricity. But if your top priority is to make your number one source of power, number one, sorry to say, but you’re in for a long wait.
- How do batteries store and release energy, and how is this different from gasoline?
- What are the main differences between rechargeable and single-use batteries?
- How do lithium-ion batteries work, and what factors contribute to their eventual degradation?
- Why is battery recycling important, and what are the potential environmental and resource conservation benefits?
- What are the challenges and barriers to battery recycling, and why is the current recycling rate for lithium-ion batteries so low?
- How can regulations and clear responsibilities help increase battery recycling rates?
- What are some potential future developments in battery technology, and how might they impact energy storage and sustainability?
- How can individuals and industries contribute to improving battery recycling processes and reducing their environmental impact?
energy – the capacity for doing work or producing heat – The sun provides the energy that plants need to grow.
storage – the action or method of storing something for future use – I need to find a storage solution for all my old books.
batteries – a container consisting of one or more cells, in which chemical energy is converted into electricity – I need to replace the batteries in my TV remote.
gasoline – a volatile flammable liquid used as fuel in internal combustion engines – I need to fill up my car’s tank with gasoline.
recyclable – able to be recycled or reused – This plastic bottle is recyclable, so make sure to put it in the recycling bin.
metals – a solid material that is typically hard, shiny, malleable, fusible, and ductile – Gold and silver are precious metals.
electrons – a stable subatomic particle with a charge of negative electricity – Electrons orbit around the nucleus of an atom.
reactions – a process in which substances are changed into different substances – Mixing vinegar and baking soda causes a chemical reaction that produces carbon dioxide gas.
rechargeable – able to be recharged or restored to full energy or capacity – I prefer using rechargeable batteries for my electronic devices.
lithium-ion – a rechargeable battery type commonly used in portable electronics – My smartphone uses a lithium-ion battery that lasts a long time.