Tech Talk: Solid State Battery Technology

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Almost all current consumer electronic products use lithium ion rechargeable batteries. Recent headlines have demonstrated that this technology involves bundling flammable technologies into a rechargeable cell and using this to keep our devices in use, and over the years, lithium ion rechargeable technology has progressed such that the cells used in batteries are operating close to their maximum theoretical energy budget: batteries will not be able to deliver much more energy by mass. We've seen different developments into battery technology such as designing rapid charging technologies or increasing the number of charge cycles the battery will last, but as we have seen sometimes rechargeable batteries can fail with explosive results. This is something that Samsung are only too aware of with this year's Galaxy Note 7 battery problems. Although it's not been confirmed yet, one school of thought believes that the membrane separating the two electrolytes was too thin and fragile and this resulted in the runaway thermal issues.

One alternative technology that has been in service for a numbers of years now is that of the solid state battery. Here, rather than using a liquid electrolyte, rechargeable batteries use a solid electrolyte. This brings about it several significant technological advantages: the batteries are inherently safer as it's much harder for the physical components to mix, there's a higher energy density (up to three times current technology) and even a longer life cycle. In other words, not only can these batteries provide more energy for our power hungry consumer electronic devices, but they'll last longer before needing to be replaced and there's less chance of them exploding. Furthermore, the technology is already being used for Internet of Things, RFID and some wearable devices, such as medical devices (pacemakers). If this sounds too good to be true, there is one aspect that we need to consider and that is how much the technology costs. This is, currently, the disadvantage of solid state battery technology because it's expensive to manufacture. Currently, a small RFID device can use a thin film battery, which will cost between $20 to $30. If there were a linear cost scale to increase the size and capacity of the battery for something capacious enough to keep a smartphone operational for a day, it would be excessive. Unfortunately, according to Doctor Lorenzo Grande "the cost per square meter increases exponentially with the size of the battery you want to make." Doctor Grande is a technology analyst at IDTechEx. In other words, solid state batteries are prohibitively expensive to construct at smartphone sizes.

The industry is certainly researching into the technology with a view to reducing the cost of manufacturing the technology. Doctor Grande considers Samsung as a likely candidate to introduce a solid state-powered smartphone in the future, even if the business loses money on each battery, given the damage to their reputation associated with the Galaxy Note 7 battery problem. However, Samsung – like arch rival LG – is keeping its battery technology cards close to its chest. It is likely that Samsung has developed new, advanced battery technologies but these are still not commercially viable and because of this, the company has not published any significant advances. Currently, there are at least eight different solid state battery technologies with a potential mobile use, but each different formulation has certain advantages and disadvantages.

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Given the increased energy capacity of solid state batteries, manufacturers might appear to face a decision between using a much smaller battery than current units for comparable battery life, or using a similar sized battery and providing up to three days of use. However, manufacturing costs will at first be very expensive in comparison with current battery technology. Even after considerable development, it's likely we will see smaller, thinner batteries fitted inside even thinner smartphones and wearables. This trend might change as the cost of solid state batteries reduces over time. There are other industries that can help drive the cost down, starting with the drone market and including the automotive sector. Doctor Grande believes that consumer electronic devices are unlikely to see solid state batteries until around 2021 or 2022 but that we will start to see solid state batteries used in drones "as early as 2017." Once the technology starts to trickle into other industries, including drones, this will encourage additional investment and this will start to both progress the technology and reduce the cost of manufacturing batteries.