ORNL solid-state 5V Li-ion battery shows cycle life of 10,000, 90% capacity retention
20 October 2014
Researchers from Oak Ridge National Laboratory have demonstrated a solid-state high-voltage (5 V) lithium battery with an extremely long cycle life of more than 10,000 cycles, with 90% capacity retention. The solid electrolyte enables the use of high-voltage cathodes and Li anodes with minimum side reactions, leading to a high Coulombic efficiency of 99.98+%.
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| ORNL solid-state Li-ion battery. Click to enlarge. |
A paper on their work is published in the journal Advanced Energy Materials.
The energy stored in a battery of a given size is proportional to its voltage. Conventional lithium-ion batteries use organic liquid electrolytes that have a maximum operating voltage of 4.3 V; operation above this limit can cause short cycle life and serious safety concerns.
However, lithium-ion-conducting solid electrolytes could enable high-energy battery chemistries by circumventing safety issues of conventional lithium batteries with liquid electrolytes. Use of a solid electrolyte would simplify the use of a Li-metal anode with its high gravimetric energy density, for example.
Toyota, for one, is working on all-solid-state batteries as a mid-term advanced battery solution. (Earlier post.)
However, achieving the required combination of high ionic conductivity and a broad electrochemical window in solid electrolytes is a grand challenge for the synthesis of battery materials, members of the ORNL team noted in a paper published in the Journal of the American Chemical Society in 2013. (Earlier post.)
In 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 cathode and Li anode at a charge voltage to 5.1V. The solid state battery retained more than 90% of its original capacity after 10,000 cycles—equivalent to more than 27 years of life with a daily charge/discharge cycle.
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| Voltage profiles of the (a) LiNi0.5Mn1.5O4 solid-state lithium battery and (b) a LiNi0.5Mn1.5O4 liquid battery discharged at different rates. The battery was charged at C/10 before each discharge measurement. Li et al.Click to enlarge. | ||
Resources
Juchuan Li, Cheng Ma, Miaofang Chi, Chengdu Liang, and Nancy J. Dudney (2014) “Solid electrolyte: the key for high-voltage lithium batteries,” Advanced Energy Materials doi: 10.1002/aenm.201401408
Looking at the graph it appears this battery has ~400 WHr/kg capacity and 10000 cycles lifetime. That's awesome. Is it going to be commercialised?
Posted by: msevior | 20 October 2014 at 04:58 AM
The first application for batteries like this would be grid storage - 10,000 cycles is ~30 years of cycling. Grid storage needs high cyclability, high efficiency and low maintenance. Things like weight and volume aren't as important.
Posted by: Anthony F | 20 October 2014 at 08:38 AM
Also ideal for HEV's and PHEV's. Would be a waste in a long-range BEV because of such high cycle life!
Posted by: Roger Pham | 20 October 2014 at 01:34 PM
huh how wasting 15% in IR is ideal for PHEV? charging probably needs another 15.
Posted by: As Aha | 20 October 2014 at 02:08 PM
Looks like an excellent phone or laptop battery, but discharge rate is too low for a car (unless you want a 500 mile range at 50 mph).
Posted by: Steve Reynolds | 20 October 2014 at 05:02 PM
You can use energy dense without power dense by using two kinds of batteries. These would be the "range extender" variety, the conventional lithium ion batteries would be for power.
Posted by: SJC | 20 October 2014 at 07:50 PM
Assuming that future extended range BEVs may have 120 to 160 kWh battery packs and that the average much lighter future BEV will need less than 20 KW to move it at 110 kph or so, the average discharge rate will be rather low.
This type of battery could easily do it.
However, recharging such batteries may represent a (time) challenge.
Posted by: HarveyD | 21 October 2014 at 04:57 PM