{"id":9749,"date":"2015-03-23T15:03:48","date_gmt":"2015-03-23T22:03:48","guid":{"rendered":"http:\/\/cafe.foundation\/blog\/?p=9749"},"modified":"2015-03-23T15:04:26","modified_gmt":"2015-03-23T22:04:26","slug":"dr-yi-cuis-latest-solid-state-electrolyte","status":"publish","type":"post","link":"http:\/\/cafe.foundation\/blog\/dr-yi-cuis-latest-solid-state-electrolyte\/","title":{"rendered":"Dr. Yi Cui’s Latest, a Solid-state Electrolyte"},"content":{"rendered":"

Green<\/a> Car Congress<\/a><\/i> reports\u00a0that, \u201cStanford researchers led by Professor Yi Cui have used ceramic nanowire fillers to enhance the ionic conductivity of polymer-based solid electrolyte by three orders of magnitude. The ceramic-nanowire filled composite polymer electrolyte also shows an enlarged electrochemical stability window.\u201d<\/p>\n

With solid-state batteries coming to the fore through efforts by Ann Marie Sastry at Sakti 3<\/a> and Qichao Hu at Solid Energy Systems<\/a>, an improved solid electrolyte would seem to offer greater battery safety and stability \u201cwhen compared with conventional liquid electrolytes.<\/address>\n
\"Solid-state<\/a>

Solid-state electrolyte provides safety and stability with much higher conductivity. \u00a0 Note much higher energy conductivity for PAN-lithium Chlorate with titanium oxide nanowires, apparently varying little with temperature changes. \u00a0Diagrams on right show difference between unconnected nanoparticles and those connected with nanowires<\/p><\/div>\n

The abstract<\/a><\/span>\u00a0for the Stanford researchers\u2019 paper in the journal <\/span>ACS Nano Letters<\/i> explains that \u201cCurrently, the low mobility of lithium ions in solid electrolytes limits their practical application. The ongoing research over the past few decades on dispersing of ceramic nanoparticles into polymer matrix has been proved effective to enhance ionic conductivity although it is challenging to form the efficiency networks of ionic conduction with nanoparticles. In this work, we first report that ceramic nanowire fillers can facilitate formation of such ionic conduction networks in polymer-based solid electrolyte to enhance its ionic conductivity by three orders of magnitude. Polyacrylonitrile (PAN)<\/em>-LiClO4 (lithium perchlorate)<\/em> incorporated with 15 wt % Li0.33La0.557TiO3 (lithium oxide, lanthanium – a rare earth – oxide, titanium oxide)<\/em> nanowire composite electrolyte exhibits an unprecedented ionic conductivity of 2.4 \u00d7 10\u20134\u00a0S cm\u20131\u00a0at room temperature, which is attributed to the fast ion transport on the surfaces of ceramic nanowires acting as conductive network in the polymer matrix. In addition, the ceramic-nanowire filled composite polymer electrolyte shows an enlarged electrochemical stability window in comparison to the one without fillers. The discovery in the present work paves the way for the design of solid ion electrolytes with superior performance.\u201d<\/span><\/p>\n

Green Car Congress reports, \u201cThey investigated the ionic conductivities of their solid electrolytes via AC impedance spectroscopy measurements with two stainless steel blocking electrodes.<\/p>\n

\u201cThe composite electrolyte with 15 wt % LLTO nanowires displayed the highest conductivity of 2.4 \u00d7 10\u22124<\/sup>\u00a0S cm\u22121<\/sup>\u00a0at room temperature\u2014about three orders of magnitude higher than that of PAN-LiClO4<\/sub>\u00a0without fillers (2.1 \u00d7 10\u22127<\/sup>\u00a0S cm\u22121<\/sup>).\u201d<\/p>\n

This jump in conductivity, coupled with materials already used in existing solid-state batteries, might lead to lighter, more energy dense cells that could be applicable in electric vehicles \u2013 in particular, light aircraft.<\/p>\n

The Nano Letters<\/i> paper concludes, \u201cOur work opens the door for novel developments of one-dimensional Li+<\/sup>-conducting ceramic materials in solid electrolytes for lithium-ion batteries.\u201d<\/em><\/p>\n

Dr. Cui is a constant presence in the blog, having created batteries literally on paper, formed the experimental basis for technology that became Amprius, a Sunnyvale, California-based manufacturer of \u201chigh energy and high capacity lithium batteries,\u201d and now working on solid-state batteries.\u00a0 He will speak at the ninth annual Electric Airplane Symposium<\/a> in Santa Rosa, California on May 2, 2015.<\/p>\n

His talk, \u201cMaterials Design for Battery Breakthroughs: from Fundamental Science to Commercialization,\u201d promises a great overview of his teams\u2019 work.\u00a0 He gives a preview in this synopsis.\u00a0 \u201cIn the past two decades rechargeable batteries have been a great success in powering consumer electronics. There is a recent strong interest in applying rechargeable batteries to electrification of transportation, which present new challenges and opportunities for batteries including energy density, cost, safety and cycle life. There I present our breakthrough battery technology enabled by novel materials design. High-energy batteries examples include silicon and lithium metal anodes and sulfur cathodes, which have 10x charge storage capacity of current technology. We also designed smart separators which could enhance the battery safety significantly. The commercialization pathway of some of these breakthroughs will also be presented.\u201d<\/p>\n