Reflections on the Safety Limits of Lithium-ion Battery from Note 7 Event

Over the past year, the U.S. Consumer Product Safety Council has repeatedly sent messages recalling batteries, snow blowers, skateboards, flashlights, and electric recliners because of fires caused by lithium-ion batteries.

In 2013, Boeing was forced to suspend all 787 jetliners due to the fire of some lithium batteries. After changing the battery and charger, and better response to the battery fire, the aircraft was allowed to resume flight.

In 2014, Boeing said after investigating an incident, "After this incident, we are still confident that we will make comprehensive improvements to the battery system of the 787 passenger aircraft, the overall performance of the battery system, and the safety of the aircraft. "

Lightweight, high energy.

Lithium is the lightest of all metals. It can put a lot of energy into a small volume and is the most perfect battery.

The market for lithium has grown from hundreds of millions in 2000 to $8bn last year, according to Albemarle, the US chemical company.

However, for the same reason, lithium-ion batteries require built-in safety mechanisms that increase production costs.

Moreover, according to the calculation of Albemarle, the price of lithium has dropped by 14% every year for the past 15 years. Lewis Larsen, chief executive of consulting firm lattice energy, says smaller companies are starting to figure out security issues.

There is no evidence that Samsung or its battery supplier is cutting corners on Note7 phones, and Tony Olson, chief executive of consulting firm D2Worldwide, believes the problem is not limited to cheap products.

Ten years ago, he ran a battery test on his laptop, stressing that the battery was in danger of catching fire. About 9.6 million laptop batteries were recalled by Sony.

But when Olson tested other laptop batteries seven years later, he found that "the battery safety design has basically not changed, although the inspection is very strict. "

Sony, Hewlett-Packard, Toshiba, and Panasonic have all recalled laptop batteries for fire hazards, according to the Consumer Product Safety Commission. Matsushita, which supplies the batteries, said the problem arose during the manufacturing process and has now been resolved.

Asked about the difficulties faced by Samsung last week, Matsushita CEO Kazuhiro Tsuga told reporters that lithium-ion batteries are prone to fire when density is increased and charging is fast.

"To balance[risk] against benefits, we put security first," says Kazuhiro Tsuga. "It is very difficult to reduce the accident rate to zero with current technology. "

Greater demand

Before the smartphone era, users didn't need too many devices -- just a few phones and a few text messages. Today, however, the telephone needs to do more and be constantly used.

For example, according to eMarketer, an advertising agency, mobile users in China spend nearly twice as much time on smartphones as they did four years ago.

This, in turn, has prompted manufacturers to make their screens bigger, making them more powerful and putting more energy into smaller spaces. But the material gets more complex, "they're not 100 % safe, never will be," says Larson.

"From a lithium-ion point of view, we think that they are beginning to reach the safety energy density limit of the technology. "

But experts are divided on this point. BrandonNg, the boss of QFE, a Hong Kong start-up, plans to sell batteries the size of refrigerators to replace diesel generators, and he believes there is still room for improvement.

"Lithium batteries still have a lot of room for growth in terms of increasing energy storage. "

New technologies to make batteries safer have long been promising, and they are about to burst into thin air.

According to Tim Grejtak, an analyst at the Ritz Institute, dozens of startups are tackling the problem, but scientific problems are hard to solve and take time.

According to Tim Grejtak, the most promising company to break through is Blue Current, headquartered in California, which is studying how to use gel electrolytes to produce high-density, low-flammable batteries.

Huqichao, the founder of the Massachusetts firm solid energy systems, which is working on a lithium metal battery, says it would cut the battery space by half. It will first be used in high-altitude drones and will be available for consumer devices, including smartphones, by 2018.

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