![\"Cubic](\"http:\/\/cafe.foundation\/blog\/wp-content\/uploads\/2015\/08\/Solid-Electrolyte-1.jpg\")
<\/a>Cubic structure of MIT\/Samsung solid electrolyte allows easy passage of ions. \u00a0Illustration shows lithium atoms in green, sulfur atoms in yellow, PS4 (phosphorus tetrasulfur) tetrahedra in purple, and GeS4 (germanium tetrasulfur) in blue. \u00a0Image: Yan Wang<\/p><\/div>\n
That has led researchers at MIT, Samsung, and in California and Maryland<\/a> to develop a solid-state electrolyte that might overcome the safety issue while providing more energy storage in a given space.<\/p>\n Yan Wang, an MIT post-doctoral student; Gerbrand Ceder, a visiting professor of materials science and engineering, and five others report their efforts and findings in the journal Nature Materials<\/em>. MIT\u2019s announcement explains that while others have attempted creation of solid replacements for liquid electrolytes (including perhaps Anne Marie Sastry of Sakti 3?) the group explains they are the first to make \u201ca formulation that fully meets the needs of battery applications.\u201d<\/p>\n Ceder makes some interesting claims, including the idea that solid-state electrolytes would make for, \u201calmost a perfect battery, solving most of the remaining issues\u201d in battery lifetime, safety, and cost.<\/p>\n \u201cCeder adds: \u2018All of the fires you\u2019ve seen, with Boeing, Tesla, and others, they are all electrolyte fires. The lithium itself is not flammable in the state it\u2019s in in these batteries. [With a solid electrolyte] there\u2019s no safety problem \u2014 you could throw it against the wall, drive a nail through it \u2014 there\u2019s nothing there to burn.\u2019\u201d<\/p>\n As significant as the safety issue is, Ceder says, \u201c\u2019With a solid-state electrolyte, there\u2019s virtually no degradation reactions left\u2019 \u2014 meaning such batteries could last through \u2018hundreds of thousands of cycles.\u2019\u201d<\/p>\n Common thinking was that solids could not conduct fast enough to be considered as electrolytes.\u00a0 Ceder says, \u201cThat paradigm has been overthrown.\u201d<\/p>\n Starting with a class of materials known as \u201csuperionic lithium-ion conductors,\u201d compounds of lithium, germanium, phosphorus and sulfur, the team turned to an \u201congoing partnership\u201d with Samsung through the Samsung Advanced Institute of Technology, conveniently located near MIT is Cambridge, Massachusetts.\u00a0 Ceder explains that the alliance, \u201chas led to important advances in the use of quantum-dot materials to create highly efficient solar cells and sodium batteries.\u201d<\/p>\n This solid-state can still function at those temperatures below -20\u00b0C, Ceder says. \u00a0It also gives a 20 to 30 percent improvement in power density.\u00a0 While this may not be the 2X, 5X or even 10X breakthrough we would love to see, the benefits in safety and longevity are certainly desirable.<\/p>\n Cubic, tetrahedral arrangements of elements tried in solid-state electrolyte<\/p><\/div>\n While some might be disappointed that a fire-proof, essentially life-time battery is not more powerful, perhaps the team can combine their findings with Samsung’s recent announcement that they have achieved a battery with double the energy density <\/a>of previous lithium ion cells. \u00a0After all, what are partners for?<\/p>\n<\/a>