A Li-ion battery that is safe, has high power and can last for 1 million miles has been developed by a team in the Pennsylvania State University (Penn State) Battery and Energy Storage Technology (BEST) Center in the United States, according to foreign media report.

Generally, electric vehicle batteries require a trade-off between safety and energy density. If the Li-ion battery has high energy and high-power density, which is required for uphill driving or merging on the freeway, then there is a chance the battery can catch fire or explode under inappropriate conditions. But materials ground tungsten carbide rods that have low energy or power density, and therefore high safety, tend to have poor performance. There is no way to find materials that can meet both safety and energy density requirements. For this reason, battery engineers opt for battery performance over safety.

Chaoyang Wang, a professor at the mechanical, chemical and materials science and engineering of Penn State, and William E. Diefenderfer Chair said: "In this work we decided we were going to take a totally different approach. We divided our strategy into two steps. First we wanted to build a highly stable battery with highly stable materials."

The second step is to introduce instant heating. About 4 years ago, Professor Wang developed a self-heating battery to overcome the problem of poor battery performance tungsten carbide burrs blank in cold weather. This type of battery can be heated in a matter of seconds with an electric current, but it can take several hours with an external heater. By heating the battery from room temperature to about 140 degrees Fahrenheit (60 degrees Celsius), the battery gets an instant boost in reactivity because the law of kinetics is that reactivity increases exponentially with temperature. Professor Wang said: "With these two steps I can get high safety when the battery is not being used and high power when it is."

The self-heating battery, called the All Climate battery, has been adopted by many car companies such as BMW and is powering a fleet of 10,000 cars, which will be used to ferry people between venues at the next Winter Olympics in Beijing, China.

BEST Center tested the safety of the Li-ion battery using nail penetration equipment, caused a short circuit, and then monitored the battery temperature and voltage. The difference in temperature for the passivated cell was 212 degrees Fahrenheit (100 degrees Celsius), while the standard battery has a temperature difference of 1832 degrees Fahrenheit (1000 degrees Celsius), which is an enormous improvement.

Because the battery is made of stable materials, it has a long cycle life. Even at 140 degrees Fahrenheit (60 degrees Celsius), the number of cycles can exceed 4,000, which means that the life span can exceed 1 million miles.

The Penn State research team's next project is to develop a solid-state battery, which tungsten carbide burrs will also likely require heating. And Tesla has previously announced a Li-Ion battery with a life of more than 1 million miles. It seems that the wider popularity of electric vehicles is just around the corner.