Why your phone battery lasts for DAYS when it’s new, but loses charge in a few hours after a year:

Scientists have finally unpicked the mystery behind why smartphone batteries have such diabolical battery life after a year or so of use.

According to the latest findings, the commonly-held belief of how a lithium-ion battery works is incorrect.

Instead of charged particles flowing in a single, uniform direction inside the battery, they move back and forth in a random pattern of movement.

According to the researchers, this knowledge could be used to create batteries that last longer and hold their charge without damaging the lifespan of the cell.

This could have applications for the mass roll-out of electric vehicles as well as improving the lifespan of billions of gadgets worldwide, scientists say.

The breakthrough study came from researchers at Stanford University, MIT and the University of Bath who discovered that our understanding of how a lithium-ion battery – the type that powers all our favourite gadgets – works, is incorrect.

It is known that charged particles flow between a positive electrode to a negative electrode through a material (electrolyte) and this movement creates a charge.

However, it was previously believed the lithium was anisotropic, a property that means it flows in a single direction, with the particles in a single, uniform route through the battery.

However, it has now been found that the reality is vastly different and the particles, known as ions, actually ebb and flow back and forth through the electrolyte.

This can create random pockets of densely packed ions inside the cell, which create large amounts of heat, damaging the lifespan of the battery.

As a result, the battery loses the ability to hold a charge and we often find ourselves relying on portable chargers more often.

William Chueh, an assistant professor at Stanford, said: ‘We used very powerful X-rays from an accelerator, and we’re using these X-rays to look into these individual nanoparticles.

‘Our original expectation was that lithium moves in certain directions only. We actually saw lithium move in the direction it’s not supposed to move.’

The research made use of the SLAC National Accelerator Lab’s facilities at Stanford, which allowed the team of scientists to look at batteries on the nanoscale.

Dr Chueh elaborates on the phenomenon and explained that previous theories did not account for how the liquid interacts with the solid.

‘Kind of like in space, we think about how the particle behaves in a vacuum,’ he said.

‘But a battery doesn’t operate in a vacuum—it operates in a liquid.’

The team believe they will be able to fix this flaw by altering the transport pathway and allowing for more durable batteries in the future.