Future batteries could keep smart devices charged for 'thousands of years'

Energy storage devices that can be charged from electricity and then slowly run out of power throughout the day have become the beating heart of today's mobile devices.

Lithium-ion batteries have revolutionized energy storage and transportation solutions from one place to another, and paved the way for a revolution in the electronic devices we use today.

Sony was the first to introduce lithium-ion batteries for commercial use in 1991 when the company was looking for solutions to extend the life of its camcorder batteries. Lithium-ion batteries are now used to power many modern electronic devices, from smartphones and laptop computers to electric toothbrushes and handheld vacuum cleaners.

Last year, three scientists behind this revolutionary invention won the Nobel Prize in Chemistry.

It is expected that we will increase our dependence on these batteries, as lithium-ion batteries are used in electric vehicles as an alternative to fossil fuels. And at a time when the share of renewable energy sources has increased in the electricity supply around the world, it is likely that we will need to produce huge quantities of batteries to store excess electrical energy to compensate for the energy shortage in times when the wind does not blow or the sun does not shine.

More than seven billion lithium-ion batteries are currently sold worldwide, and this number is expected to increase to more than 15 billion by 2027.

Lithium-ion batteries, however, are not without drawbacks. Their ability to hold and store energy for long periods of time with repeated charging decreases, and their performance deteriorates when the weather is very hot or very cold.

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Concerns were also raised about the safety and impact of these batteries on the environment. Lithium-ion batteries may burn or explode in certain circumstances, and the extraction of the metals used in their manufacture may cause severe damage to the environment and societies.

This prompted scientists around the world to develop new types of batteries that avoid these defects. Some of them resorted to harnessing a range of new materials, from diamonds to a kind of fruit that has an unbearable smell, in the hope of finding new solutions to provide energy for electronic devices in the future.

Lithium-ion batteries work by allowing charged lithium ions to transfer electricity from one end to the other through a liquid conductive solution known as an electrolyte. Lithium-ion batteries have attracted attention due to their "high energy density", that is, the maximum energy stored by the battery compared to its size. Lithium-ion batteries have a higher energy density and voltage difference compared to the batteries available in the market.

Batteries consist of three main components, the negative electrode and the positive electrode, and between them is an electrolyte. The two poles alternate roles, as the anode (anode) may become the positive pole and the cathode (cathode) the negative pole during the charging process, and vice versa during the charge-discharging process.

The cathode in lithium-ion batteries is made from one of the metal oxides with one of the metals. When charging, the lithium ions and electrons move from the cathode to the anode, where they are stored in the form of electrochemical energy, by a series of chemical reactions in the electrolyte, driven by the electrical energy that flows from the charging circuit.

When the battery is in use, lithium ions flow in the opposite direction, from anode to cathode through the electrolyte, while electrons flow through the electrical circuit of the device that powers the battery.

The materials from which the cathode and anode are made have changed over the years, which has contributed to improving the capacity of lithium-ion batteries and energy density, and the cost of batteries has decreased a lot compared to the past.

Moro Basta, a materials scientist at the University of Oxford and supervisor of the second phase of lithium-ion batteries at the Faraday Institution, is looking to improve the energy density of lithium-ion batteries and increase their efficiency so that they do not decrease with repeated charging.

This is why Basta is focusing on replacing the flammable liquid electrolyte in lithium-ion batteries with a solid material made of ceramic. The use of the solid material contributes to reducing the risk of ignition of the aqueous solution in the event of a short circuit, as happened in 2017, when Samsung withdrew 2.5 million Galaxy Note 7 devices after battery ignition incidents.

Solid batteries may contribute to preventing combustion risks in the future, as it was discovered that the electrolyte made of polymer gel used in most portable electronic devices is also flammable.

The solid battery allows the use of lithium metal instead of graphite used in the manufacture of the anode, which contributes to a significant increase in the amount of energy stored in the battery. This will affect the efficiency of electric cars.

Each electric car now contains the equivalent of a thousand batteries used in "iPhone" phones, and the use of solid batteries in electric cars will contribute to the lengthening of the trips that these cars take before the charge runs out.

The demand for batteries will rise in the coming years, coinciding with the shift towards electric transportation and the penetration of portable electronic devices in all aspects of our lives. Therefore, the search for alternatives to lithium may become necessary to mitigate its repercussions on the environment.

The lithium triangle, which includes parts of Argentina, Bolivia and Chile, accounts for more than half of the world's reserves of this metal. But extracting it from the salt flats requires huge amounts of water to purify the lithium-rich salts and filter them to obtain pure lithium salt. In Chile, one million liters of water is used to produce 900 kilograms of lithium.

Environmental authorities in Chile have warned that the amounts of water used to extract minerals, especially lithium and copper in the region, exceed rates of replacement by rainwater and snow.

Researchers at the Karlsruhe Institute of Technology are developing batteries using different anode components, such as calcium or magnesium. Calcium is the fifth most abundant chemical element in the Earth's crust, but research to improve battery performance using calcium is still in its infancy.

Research on the use of magnesium in batteries has shown promising results so far, particularly in terms of energy density, and there are plans to put it into commercial use in the future.

Some searched for materials that do not require extraction processes, such as wood. Liangping Hu, director of the Center for Materials Innovation at the University of Maryland, recently developed a battery using porous bits of wood to make electrodes, in which metal ions interact to generate electric charges.

These batteries build on years of research into the energy-storing abilities of wood, including research on tinning wood-cellulose fibers. And because wood has a natural ability to absorb nutrients, these electrodes will store metal ions, and won't swell or shrink like the electrodes in lithium-ion batteries.

However, batteries containing wood fibers and tin are still being researched, and Liangping's team is looking forward to using them to charge laptops in the future.

These batteries lose their ability to hold the electric charge relatively quickly, as the prototype of these batteries retained only 61 percent of the storage capacity after 100 recharging cycles.

Cobalt is also widely used in modern batteries, and is found in most batteries with lithium in the cathode. The extraction of cobalt causes the release of toxic gases that harm the communities that live near the mines, in addition to its negative consequences for the environment. Reports revealed the use of children as laborers in cobalt mines, especially in the Democratic Republic of the Congo, which hosts half of the cobalt mines in the world.

Laws were filed against Apple, Tesla and Microsoft recently over deaths resulting from cobalt mining.

This has prompted Judy Lutkenhaus, a chemical engineer at Texas A&M University, to develop alternatives to lithium-ion batteries using proteins, the complex molecules that living organisms produce and use. The anode is usually made of graphite, and the cathode is made of metal oxides containing elements such as cobalt. Lutkenhaus believes that it is possible to replace these minerals with organic materials.

These batteries, which are based on organic materials, address another environmental problem. In the event that lithium-ion batteries are disposed of in landfills, metals and electrolytes may leak into the environment and cause double damage. It is estimated that only 5 percent of the lithium-ion batteries used in smartphones sold annually are recycled.

Power from fruit

A group of researchers is looking for new ways to power mobile devices while tackling the problem of food waste. Vincent Gomes, a chemical engineer at the University of Sydney, and his team turn the stinky waste of durian and jackfruit, the world's largest fruit, into supercapacitors capable of charging mobile phones, tablets and laptops in minutes. Ultracapacitors are an alternative way to store energy.

Supercapacitors are usually made of expensive materials like graphene, but Gomez's team turns waste durian and jackfruit into carbon aerogels - ultralight, porous solids - with exceptional natural energy storage properties.

The team heats the spongy, inedible pulp of the fruit, freeze-dries it, then bakes it in an oven at temperatures above 1,500 degrees Celsius, then molds the black, light, porous product into electrodes for low-cost supercapacitors.

Supercapacitors can be charged in just 30 seconds and can be used to power many devices, such as mobile phones. The team hopes to use these supercapacitors to store electricity generated from renewable sources to power vehicles and homes.

Before these new uses for durian were discovered, the waste of this foul-smelling fruit made headlines, with more than 70 percent of durian fruit being thrown into the trash. The repulsive stench of its waste disrupted a plane takeoff in Indonesia and the evacuation of a library at the University of Canberra last year.

Mikhail Astakhov, a physicochemist at the National University of Science and Technology in Moscow, conducted research to convert pigweed, a herb that contains toxic sap that can cause burns and blisters on human skin, into a raw material for manufacturing supercapacitors capable of charging the phone.

Batteries Forever

Other researchers are working on other problems with lithium-ion batteries, beyond their environmental consequences. Tom Scott, a materials scientist at the University of Bristol, believes that lithium-ion batteries will be supplanted by new means of energy storage in many contemporary uses, especially in extreme environments, over the next century.

Scott and his team have developed batteries made of diamond. The team developed synthetic diamonds that contain the radioisotope carbon-14, to obtain batteries that derive energy from radioactive isotopes, to produce continuous current and last for thousands of years.

When the radioactive isotopes inside the diamond crystals decay, they release high-energy electrons. These flowing electrons may be harnessed to produce an electric current. The researchers say that the radioactivity outside the battery remains at safe levels.

The team developed a prototype of the "diamond battery", using artificial diamonds, and the researchers exposed it to radiation from the nickel-63 isotope, so that electrons flow through the diamond. The researchers are working on developing a type of diamond battery using the carbon-14 isotope extracted from graphite blocks used in nuclear power plants.

Scott and his colleagues hope that these batteries will provide a solution to the problem of nuclear waste after the nuclear power plants are out of service, by converting them to long-term batteries.

While chemical batteries such as lithium-ion batteries perform poorly at high temperatures, diamond batteries perform efficiently in harsher environments, where used batteries are difficult to replace, such as in space, on the ocean floor, or on top of volcanoes. It may represent an ideal solution for satellites and automatic sensors, so as not to stop working.

These batteries are very small, says Scott. The researchers developed diamond batteries that generate an electrical voltage of 1.8 volts, like conventional small batteries, and these batteries are rechargeable, but Scott says that charging them requires placing them for a few hours inside the reactor core to reach the original efficiency.

Thanks to the continuous current generated by the decomposition of radioactive material, these batteries produce electricity for thousands of years, as the half-life of the carbon element (ie when its radiation intensity is reduced by half) is 5,730 years.

These batteries will not be very expensive either, even though they are made of diamond. Scott predicts that ultra-long-life diamond batteries will become commonplace in our homes, perhaps in fire alarms, remote controls, or medical devices, such as pacemakers or hearing aids, within the next decade or two.

Maybe we will never need to replace damaged fire alarm batteries in the middle of the night again.