Will Nuclear Batteries Revolutionize Battery Life?

Will Nuclear Batteries Revolutionize Battery Life?

Will Nuclear Batteries Revolutionize Battery Life?

With the recent release of the iPhone 7 Plus, Apple announced that this latest version delivers the best battery life ever in an iPhone. But while the iPhone 7 Plus represents an improvement on existing lithium-ion battery technology, it shouldn’t be considered a entirely revolutionary breakthrough. For such a breakthrough, some researchers are experimenting with nuclear batteries.

Lithium-Ion Batteries

All iPhones use lithium-ion batteries , the most popular type of battery for smartphones and other home electronics. They are also used in hybrid electric vehicles. Li-ion batteries work by moving lithium ions between the battery’s electrodes when discharging and back when charging up.

Li-ion batteries possess significant advantages over older batteries such as nickel-cadmium. They have higher energy density and self-discharge more slowly, giving longer life. They don’t need priming, require low maintenance and can be adapted for versatile use. And they’re steadily improving, as seen in the increase from the  iPhone 6s’ 14 hours of talk time  and 10 hours of standby to the iPhone 7’s 21 hours of talk time and 16 hours standby.

But lithium-ion batteries are vulnerable to being overcharged and discharged too much, requiring protective measures to avoid prematurely wearing out the battery. They age proportionately to their number of discharge cycles, giving them a limited lifespan. They can also face air travel restrictions and are expensive, costing 40 percent more than their nickel-cadmium counterparts.

The iPhone 7 meets users’ demands for a longer-battery iPhone and builds on lithium-ion technology, but creating a better battery could mean making use of other energy sources.

Nuclear Potential

Nuclear batteries represent more revolutionary potential. Nuclear batteries have been around since the beginning of the 20th century, but the type of nuclear battery most promising for smartphones  uses an advance on a specific type of process to generate electricity known as a betavoltaic process.Betavoltaic processes use the beta radiation emitted by radioactive elements to generate electron flow between two electrodes that have a conductor such as silicon placed between them. The hydrogen ion tritium is often used as a source of beta radiation for nuclear batteries, so nuclear batteries are often called tritium batteries.

Beta radiation is relatively safe to work with compared to other forms of nuclear radiation such as gamma rays because it can be blocked by a thin aluminum strip. However, beta radiation is still dangerous if not blocked, so creating a safe case is one challenge in creating a practical nuclear battery for popular use.

Betavoltaic cells are not efficient, lose power output over time and can damage semiconductors. Currently nuclear batteries are mainly used for specialized applications where long battery life with low power output is required, such as implanted medical devices and military and space applications.

Making Nuclear Batteries Practical for Larger Devices

University of Missouri researchers recently discovered that adding water to betavoltaic batteries enables the water to better absorb beta rays and also generates free radicals and electricity by splitting the water molecules. For a radiation source, the researchers used strontium-90, which has a half-life of 28.79 years. Cornell and University of Wisconsin researchers are also exploring ways to create nuclear microgenerators by harvesting radioactive decay from materials with thousands of times the energy density of lithium-ion batteries, enough to power micro-sized devices for decades.

Chinese websites have advertised  American-made nano-tritium batteries as 20-year batteries for portable devices, but the types of batteries advertised only generate a few nanowatts of energy to power micro-sized devices such as pacemakers, not enough energy to power smartphones or car batteries.

The next step to make nuclear batteries practical would be to combine the energy from microgenerators to serve as trickle chargers for existing batteries. Theoretically, this could produce smartphone batteries that would need charging only every few months.