Two Chinese-born scientists at DeakinUniversity in Australia have used a common commercial polymer to create a solid-state electrolyte, opening the door to doubling the energy density of solid-state lithium-ion batteries and saving them from catching fire or overheating and exploding, as has happened previously with Samsung phones.
This means lithium-ion batteries will no longer be a fire hazard because the volatile liquid electrolytes used in them will be replaced by solid polymer materials, said Dr. FangfangChen and Dr. WangXiaoenWang, researchers at the university’s Institute for Frontier Materials.
In April 2017, two researchers at the University of Texas announced a low-cost all-solid-state battery that won’t burn, one of whom is John Goodenough, co-inventor of the lithium-ion battery.
Dr. Chen said the duo has reshaped the way polymers and lithium salts are used for each other, eliminating the often highly flammable nature of traditional lithium-ion batteries. The currently commonly used liquid electrolyte, which is highly volatile, will be replaced by a solid polymer material.
“All of the products we use to make the battery process safer have already been introduced to the market. Polymers have been used as battery conductors for more than 50 years, but we are the first to use existing commercially available polymers in an improved way.”
“Our findings suggest that the next generation of batteries will be safer and will perform even better.”
“From the results we found, this electrolyte will allow us to use lithium metal anodes, which will allow future batteries to last twice as long as they currently do on a single charge. In addition, the size and weight of the battery could be cut in half without affecting the time to normal performance.”
Dr. Wang said this could be a way to double the energy density of lithium-ion batteries, which currently peak at about 250Wh/kg (in TSLA’s Model 3 battery pack) in a commercial setting. Increasing it to 500Wh/kg could extend the range of electric vehicles.
Dr. Chen said this discovery could change the way batteries are handled in everyday life.” We did this by making the lithium ion weakly bonded to the polymer to form a solid polymer electrolyte. We believe that this is the first clear and useful example in science of transporting lithium ions without liquid and efficiently.”
In the future, they envision battery-related devices that can be safely packed in airplane luggage or electric vehicles that do not pose a fire hazard to drivers or emergency services personnel as they do today.
The process has already been demonstrated in button batteries, and the next step is to expand the batteries to larger applications, such as for smartphones, computers and electric vehicles, Dr. Wang said, adding that fabrication and testing of pouch batteries has already begun at Deakin University’s state-of-the-art Battery Technology Research and Innovation Centre in Australia.” Once the pouch size is reached, we hope to attract collaboration with industry partners.”
The paper has been published in in the peer-reviewed journal Joule.