The methods of powering portable electronics are problematic.
Almost every modern portable device, from cell phones to electric vehicles, uses lithium-ion batteries. The United States Department of Energy describes lithium-ion batteries as “the ubiquitous power supplier in all consumer electronics.” Lithium-ion batteries have a high energy density, meaning they can store large amounts of energy in a small, lightweight form factor. They have a high power output, which is especially important for energy-guzzling devices like laptops and electric vehicles. Lithium-ion batteries also have a low self-discharge rate, allowing them to hold their charge for a long time. However, even though they are reusable, recyclable, and have a long life cycle, the technology sector’s increasing reliance on these batteries still takes a toll on the planet.
Lithium-ion batteries are the preferred power source for most applications because of their reusability. Lithium is a highly reactive element, requiring that only lithium compounds be present in its operation. Every lithium battery uses a cathode (the positive electrode), a graphite anode (the negative electrode), and an electrolyte solution as a conductor. Manufacturers use nano-structured lithium titanate as an additive to enhance the performance of the graphite anode and increase its life cycle. Six carbon (graphite) atoms bind to a single lithium-ion, and a single silicon atom can bind to four lithium ions, giving the lithium-ion battery its capacity. When the battery charges, a voltage is applied to the terminals, allowing the lithium ions to move from the cathode to the anode through an electrolyte solution (typically a lithium salt dissolved in an organic solvent). When discharging, the lithium ions move from the anode to the cathode. This reversible movement of the lithium ions allows the reuse of the battery. As lithium ions move through the electrodes, they generate an electrical current. A separator between the anode and cathode prevents the electrodes from contacting and short-circuiting the battery.
Other batteries make up a smaller portion of the market scale. Lead-acid batteries are another popular energy storage tool in backup power systems, renewable energy storage, industrial equipment, marine vessels, and off-grid living due to their low costs, durability, safety, and reliability. They are best known for their use in combustion engine vehicles to power the starter motor. Alkaline batteries typically power low-draw electronics, such as remote controls, flashlights, clocks, and portable radios. These must be replaced after a total drain, although they are recyclable. The low power draw of their intended applications means alkaline batteries are still widely used despite the growing popularity of rechargeable lithium-ion batteries.
As a result of their chemically reactive nature, all batteries will eventually degrade. For lithium-ion batteries, this usually means an age-related capacity loss within the electrodes. During charging and discharging, the electrodes experience chemical reactions that form solid-electrolyte interface layers on their surface, increasing their thermal resistance and reducing the battery’s capacity over time. This process is exacerbated by fully discharging the battery before recharging it, causing more strain on the battery in a single charge-discharge cycle. High temperatures can also accelerate this degradation process, as exposing the battery to high temperatures increases the rate of chemical reactions within the electrodes, leading to faster capacity loss. It is difficult to prevent this on commonly-used, portable devices like smartphones, so these batteries may only last for two to three years, or around 300 to 500 charge cycles, before degrading significantly, warranting a replacement or more frequent charging of the device.
As a lithium-ion battery degrades, users commonly notice that a device has a shorter usage time between charges. These are early signs of problems that can later progress to sudden shutdowns, increased heat generation, slower charging, or battery swelling, which can be dangerous.
Many manufacturers charge a hefty fee to replace the battery. Some devices have such complicated designs that they require special tools or knowledge to repair, which may force consumers to buy a new device even if their old one still works. The right-to-repair legislative movement, which has gained popularity in recent years, seeks to make it easier and cheaper for consumers to fix their products by requiring manufacturers to share information, provide diagnostic tools, and supply parts, allowing them to extend the lifespan of their products. In the case of lithium-ion batteries, the right-to-repair movement could lead to greater availability of batteries and service options, forcing manufacturers to charge competitive prices rather than engage in monopolistic competition. In Europe, companies must supply parts for their products for up to 10 years. U.S. President Biden signed an executive order in July 2021 directing the FTC to draft new right-to-repair regulations. Some states have already passed right-to-repair legislation.
One concern about the widespread use of lithium-ion batteries is their environmental impact during manufacture and disposal. These batteries require lithium which usually requires extraction from underground brine deposits. But these brine deposits must be drained first, which can deplete groundwater resources. Furthermore, the extraction process can contaminate the surrounding water sources with heavy metals if the extracted brine is not treated correctly before being returned to the water table. Mining cobalt and nickel can also contribute to deforestation, land degradation, and water pollution. The refinement of aluminum, copper, and lithium materials generates greenhouse gasses. And the disposal of used batteries can be dangerous as lithium-ion batteries contain toxic and flammable materials. If not recycled properly, they can leach into soil and groundwater or ignite and release fumes into the air, harming wildlife and ecosystems. If materials such as lithium, cobalt, and nickel are not extracted from recycled batteries, more mining will be needed to produce them. These environmental impacts can add up when more lithium-ion batteries are needed to power an increasing number of electronics.
Some renewable alternatives to fossil fuels require lithium-ion batteries due to their inconsistent energy generation, including wind and solar solutions. Additionally, some utility companies have proposed installing batteries within the grid to store excess energy during low-use hours to reduce the need for power plants to run at full capacity during peak hours. However, while these would reduce carbon emissions from fossil-fired power plants, they have a hidden environmental cost as these solutions would require the manufacture of new lithium-ion batteries.
Fire risk is a growing concern among consumers as lithium-ion batteries become increasingly common in mass-produced electronics manufactured on tight deadlines. Since they contain a flammable electrolyte solution and a highly reactive lithium-based anode, there is a risk of a thermal runaway that can cause a fire or explosion. Additionally, lithium-ion battery fires can release toxic fumes such as carbon monoxide and hydrogen fluoride, which can be dangerous for humans. Some infamous examples of lithium-ion battery fires were hoverboard fires. Shortly after their launch in 2015, many self-balancing scooters overheated and sparked fires due to poor insulation, charging too quickly, or overcharging. The U.S Consumer Product Safety Commission estimated these incidents caused over $2 million in property damage and were caused by a lack of quality and safety inspection from their manufacturers in China, leading the commission to issue a recall of half a million of the scooters in July of 2016. CPSC Chairman Elliot F. Kaye stated that “all of the hoverboard models included in this recall were made with fundamental design flaws that put people at real risk,” and “they were made and sold without a safety standard in place.” Many local governments also took action and restricted or outright banned hoverboards in public places. While most of these bans have since expired, these incidents stained the reputation of hoverboards in consumers’ eyes.
Lithium-ion battery fires are difficult to extinguish due to their chemical properties. When this type of battery overheats or experiences a short circuit, it can cause a rapid and uncontrolled release of energy, leading to a thermal runaway reaction that generates heat, gas, and flames. Traditional fire suppression methods, such as water or foam, can react with the lithium in the battery, causing the fire to intensify. Special extinguishing agents, such as dry powders like sodium bicarbonate or potassium bicarbonate, are often required to smother the fire and absorb the heat. Water mist or a thermal blanket can reduce the battery’s temperature and prevent reignition.
Manufacturers of lithium-ion batteries are exploring new ways to improve longevity due to environmental and safety concerns. One of these strategies includes optimizing their charging and discharging cycles, which involves carefully monitoring and controlling current into and out of the battery to prevent overcharging or overheating, extending the battery’s lifespan. Another strategy is incorporating advanced battery management systems that use algorithms and sensors to monitor battery performance and adjust charging and discharging patterns in real time, reducing overcharging and overheating by maintaining optimal conditions. Some companies are developing solid-state lithium-ion batteries that use a solid electrolyte instead of a liquid one, which can improve safety and reduce flammability.
As the technology sector becomes more reliant on lithium-ion batteries as the backbone of energy storage, their flaws often go unnoticed until they fail. Thus, manufacturers must ensure their batteries are safe for use in the devices that power the globe.