One of the most challenging and limiting factors in the development of many emerging technologies is the problem of battery power sources. Battery capability determines how far an electric car can go and how easy and fast it might be to charge; solar panel systems rely on rugged batteries to keep them working; personal devices from mobile phones to tablets and GPS systems; industrial applications like airplanes, alert systems, and many other technologies require batteries – and yesterday’s batteries are not doing the trick. Batteries for these emerging technologies must be able to hold sufficient charge for their purpose, be rugged and lightweight, be cost-effective, quick to charge and slow to discharge, and – possibly most importantly of all – be safe to use and easy to dispose of.
A lithium-ion battery supplies power by sending lithium ions from a negative electrode to a positive electrode using a liquid conductor. When charging, the process happens in reverse. Electrodes themselves can be made of different materials, such as cobalt, nickel, manganese, or graphite, none of which absorb enough ions to meet the increasing demands of technology. Better materials for absorption, such as tin, are being considered. Other attempts to improve battery technology include replacing liquid with air as the conductor, or using sodium, aluminum, or another metal in place of lithium. Different combinations of metals and electrode materials are all being tested.
Many current devices rely on lithium-ion batteries, which in addition to having insufficient storage, come with dangerous functional errors such as overheating, swelling of the electrodes, fire, explosion, and leaking.
One of the most promising alternatives is the development of solid-state batteries. In solid-state technology, electric current moves strictly within solid elements and compounds, permitting more of the ions to be absorbed. In the case of batteries, solid-state means using solid electrolytes instead of liquid electrolytes in lithium-ion batteries.
The developer of solid-state batteries, John Goodenough, also worked on development of the lithium-ion battery during the 1970s and 1980s, and received the Charles Stark Draper Prize in 2014 because of his work on that technology. Convinced that better materials would produce a better battery, Goodenough has continued to work to improve battery technology, and is now an advocate of solid-state technology. In his paper titled “Alternative strategy for a safe rechargeable battery,” published in the Journal of Energy and Environmental Science in February of 2017, Goodenough says of solid state batteries: “Cost, safety, energy density, rates of charge and discharge and cycle life are critical for battery-driven cars to be more widely adopted. We believe our discovery solves many of the problems that are inherent in today’s batteries.”
These batteries meet the requirements for better batteries. They last longer, charge faster, are small and light enough for devices, rugged enough for cars and airplanes, are cheap and cost-effective, and even are superior in terms of power storage. Solid-state batteries also offer the ability to test and use a wider range of materials, including alkali-metal positive terminals, which would increase the energy density of the battery’s negative terminal. Because solid-state batteries have high-conductivity at cold temperatures they will be more reliable in sub-zero weather, a current problem for smartphones and vehicles that must operate in a variety of environmental conditions.
Companies such as Samsung and Toyota are expressing interest in the technology. Samsung believes that their battery may be ready in only a few years, and Toyota is working on a similar battery for electric cars and projects introducing the new battery into consumer vehicles by 2020.
Though battery technology has continued to improve incrementally, solid-state batteries offer the greatest chance of a technological leap since lithium-ion batteries arrived on the market, which is great news for the emerging technologies that depend on them.