{"id":9373,"date":"2014-10-21T08:53:00","date_gmt":"2014-10-21T15:53:00","guid":{"rendered":"http:\/\/cafe.foundation\/blog\/?p=9373"},"modified":"2014-10-21T08:53:00","modified_gmt":"2014-10-21T15:53:00","slug":"ornl-makes-two-two","status":"publish","type":"post","link":"http:\/\/cafe.foundation\/blog\/ornl-makes-two-two\/","title":{"rendered":"ORNL Makes It Two for Two"},"content":{"rendered":"

Oak Ridge National Laboratory has announced that their researchers have <\/span>built and demonstrated a high-voltage (5 V) lithium, solid-state battery <\/a>with a usable life of more than 10,000 cycles, at the end which test the battery retains more that 90-percent of its original capacity.\u00a0 That makes two such claims in a week, with ORNL\u2019s battery comparable to that developed by Nanyang Technology University (NTU) and <\/span>reported on in this blog<\/a> last week.<\/span><\/p>\n

\"ORNL<\/a>

ORNL solid state battery shows high Coulombic efficiency, high capacity retention after 10,000 cycles<\/p><\/div>\n

ORNL points out that, \u201cFor a given size of battery, the energy stored in a battery is proportional to its voltage. Conventional lithium-ion batteries use organic liquid electrolytes that have a maximum operating voltage of 4.3 V. Operating a battery above this limit causes short cycle life and serious safety concerns.\u201d<\/p>\n

\u201cIn this latest study, the Oak Ridge team replaced the conventional liquid electrolyte with a ceramic solid electrolyte of lithium phosphorus oxynitride (Lipon), and used a LiNi0.5Mn1.5O4\u00a0cathode and Li anode at a charge voltage to 5.1V.\u201d<\/p>\n

The abstract <\/a>for Juchuan Li, Cheng Ma, Miaofang Chi, Chengdu Liang, and Nancy J. Dudney\u2019s paper, \u201cSolid electrolyte: the key for high-voltage lithium batteries,\u201d in Advanced Energy Materials <\/i>shows that the team used an entirely different chemistry from NTU\u2019s titanium oxide-based design.<\/p>\n

\"Voltage<\/a>

Voltage profiles of the (a) LiNi0.5Mn1.5O4 solid-state lithium battery<\/p><\/div>\n

\"Voltage<\/a>

(b) a LiNi0.5Mn1.5O4 liquid battery discharged at different rates. The battery was charged at C\/10 before each discharge measurement<\/p><\/div>\n

This work demonstrates that replacing the conventional liquid electrolyte with a ceramic solid electrolyte of lithium phosphorus oxynitride (Lipon) eliminates the limit of conventional lithium-ion batteries. A model battery of LiNi0.5<\/sub>Mn1.5<\/sub>O4<\/sub>\/Lipon\/Li has been operated over 10,000 cycles at a charge voltage to 5.1V.\u00a0 The solid state battery retains more than 90% of its original capacity after 10,000 cycles. Such a battery has a cycling lifetime of more than 27 years with a daily charge\/discharge cycle, exceeding the lifetime of most devices and even vehicles. This work infuses new life into the existing chemistry of high-voltage lithium batteries. \u00a0<\/i><\/p>\n

Here, readers can see the <\/span>first page of the group\u2019s report<\/a> (with the following five pages coyly shaded to enforce payment of standard fees journals charge for enhancing your knowledge).\u00a0 Seeing more costs extra, the scientific equivalent of a peep show.<\/span><\/p>\n

Along with NTU\u2019s work, Sakti3<\/a> and Toyota<\/a> have recently released information on solid-state batteries that show great promise for higher energy density, greater safety and longer lives for batteries.<\/p>\n