New silicon-sulfur battery built on 3D graphene shows excellent performance
28 April 2016
Researchers at Beihang University in Beijing have developed a new Li-sulfur battery using honeycomb-like sulfur copolymer uniformly distributed onto 3D graphene (3D cpS-G) networks for a cathode material and a 3D lithiated Si-G network as anode.
In a paper published in the RSC journal Energy & Environmental Science, they reported that the full cell exhibits superior electrochemical performances in term of a high reversible capacity of 620 mAh g-1, ultrahigh energy density of 1147 Wh kg−1 (based on the total mass of cathode and anode), good high-rate capability and excellent cycle performance over 500 cycles (0.028% capacity loss per cycle).
Lithium-sulfur (Li-S) batteries are of great interest as next-generation energy storage solutions, especially for electric vehicles, due to their high energy density, low production cost and environmental friendliness.
A number of challenges—in both sulfur cathode and lithium-metal anode—are retarding their commercialization, however. On the cathode side, the inherent insulation of sulfur (5×10-30 S cm-1) and high solubility of polysulfide intermediates commonly cause large active-material loss and poor cycle performance.
A number of approaches have been taken to address these cathode issues, including embedding sulfur into various porous carbons such as activated carbons, macroporous, mesoporous and microporous carbons, generating sulfur-carbon hybrids with well-designed nanostructures.
While this has improved overall electric conductivity and inhibited loss of active materials, restricted pore volumes still limit the contents of sulfur and polysulfides.
Another cathode strategy has involved the use of sulfur copolymer; this has shown good inhibition of polysulfide dissolution, but needs improved electric conductivity.
On the anode side, the lithium-metal anode reacts with the commonly used organic electrolytes forms lithium dendrites during cycling, resulting in short life and sever safety issues.
Alloy-type anodes are potential alternatives because of similar voltage plateaus to lithium. A number of approaches have been proposed, including the use of Si nanowires and lithiated Si/SiOx nanospheres.
Thus, a new type of silicon-sulfur battery built from silicon-based anode and sulfur-based cathode is becoming one of next-generation Li-S batteries to overcome their severe cyclability and safety problems. However, the researches of emerging silicon-sulfur battery including the configurations, design and fabrication of appropriate and mutual matching anodes and cathodes are still in the infancy.
Herein, we develop a new configured lithiated silicon-sulfur battery with well-designed three-dimensional (3D) sulfur co- polymer cathode and lithiated silicon anode onto graphene networks. Our 3D sulfur copolymer cathode is synthesized through the thermal copolymerization of sulfur with 1, 3- diisopropenylbenzene (DIB) onto 3D graphene (3D G) network, which can significantly improve the electric conductivity of sulfur copolymer-based cathode. Remarkably enough, the re- sultant sulfur copolymer is anchored closely onto graphene skeleton in the state of separated and individual honeycombs with multi-sized pores, which not only facilitate the easy access of electrolyte, but also can efficiently restrain the dissolution of polysulfides and accommodate their large volume change during lithiation-delithiation processes. Coupled with our 3D lithiated silicon-graphene network as anode, a full lithiated silicon-sulfur battery with a high stability reversible capacity of 620 mAh g-1 based on the total mass of both cathode and anode, good high-rate capability, ultrahigh energy density (1147 Wh kg−1 based on the total mass of both cathode and anode) and excellent cycle performance (0.028% capacity loss per cycle over 500 cycles) is achieved, providing the best reported electrochemical performances for lithiated silicon-sulfur batteries to date.
—Li et al.
| Electrochemical performances of full lithiated silicon-sulfur battery built from 3D cpS-G networks cathode and 3D lithiated Si-G anode. a) Schematic illustration of a new configured lithiated silicon-sulfur battery onto 3D graphene networks. b) Selected voltage profiles of lithiated silicon-sulfur battery from 1st to 100th at 0.27 A g-1 based on the total mass of cathode and anode). c) Selected voltage profiles of lithiated silicon-sulfur battery at various current densities from 0.27 to 2.7 A g-1. d) Rate capabilities of Si-S battery and e) long cycle performances of full lithiated silicon-sulfur battery built on 3D graphene. Li et al. Click to enlarge. |
Resources
Bin Li, Songmei Li, Jingjing Xu and Shubin Yang (2016) “A new configured lithiated silicon-sulfur battery built on 3D graphene with superior electrochemical performances” Energy Environ. Sci. doi: 10.1039/C6EE01019A
With the exception of depreciation, it sounds good. Approx. 85% remaining capacity (500 x 0.028%) after 500 cycles is nothing to brag about. 85% after 5000 cycles, that would be great.
Posted by: yoatmon | 28 April 2016 at 03:33 AM
85% of 1.2 kWh/kg after 500 cycles is going to sell like hotcakes for personal electronics.
Posted by: Engineer-Poet | 28 April 2016 at 07:16 AM
After more fine tuning, to extend number of cycles (duration) to 2000 or so, this could be the foundation for future 5-5-5 batteries, if they can be mass produced at a very low cost.
Affordable extended range (500+ Km) BEVs 'may' become a reality by 2025/2030 or so?
Posted by: HarveyD | 28 April 2016 at 07:27 AM
It make so sense to buy an ev if you lose as much as 0.028% of capacities on each cycles because these mad loss of capacities lead on each cycles to increased drag resistance and each cycles is worst than the previous one leadind to a brick battery over one or two years especially if you often fast charge your ev. That's why ev manufacturers didn't agree on any fast charge uniform norm and protocol. Also ev manufacturers don't know nothing about batteries and they buy it on this new mandated subsidies program where low quality electronic is obvious. This is a financial hole enforced by international high financial banks to ruin every manufacturers, goverment and consumers, eternal poverty.
Small gas cars is the solution as they are constant impedance contrary to these batteries that also self discharge, especially in cold or hot climate.
Stop this damaging mandate and invent a new synthetic fuel as i said long time ago
Posted by: gorr | 28 April 2016 at 07:35 AM
gor, are you mentally sane ?
Harvey, you have revised your prediction ? it is no longer 2020 the dead line for 500miles highway capable ev ?
Posted by: Treehugger | 28 April 2016 at 08:16 AM
HarveyD and gor are both Canadians. I think it's something in their media.
Posted by: Engineer-Poet | 28 April 2016 at 08:26 AM
Why do we have to change the infrastructure system from perfectly working not subsidized gasoline low cost cars to heavily subsidized underperforming evs and very costly not standarzed rechargers infrastructure. Recharging at home is a nightmare for 80% of resident in apartments worldwide and anyway most electricity and battery combo is polluting by coal and heavy chemical in batteries. Stop these deadly political turmoils created by maniacs not understanding the impedance of energy systems.
Posted by: gorr | 28 April 2016 at 09:55 AM
Seriously, for gor, he has had some health issues and I suspect at times meds make his posts a little more "far out" than others, plus English is not his first language. So I cut him some slack as some days his posts make better sense than others.
Harvey is just an optimist at heart. Everything he sees is very shaded by hopes of a positive future so I may disagree with him on things (mostly H2) but you gotta admire his positive outlook on life :)
Posted by: DaveD | 28 April 2016 at 10:50 AM
This looks promising. The 500 cycles is a bit short, but the graph is relatively flat after the first 50 cycles so would it stay that way and be 80% at 2,000 cycles or would it degrade and be more like 60% after 2,000 cycles.
Those two answers are VERY different for the viability of this battery. Obviously, improvements on that front will be welcome/needed regardless.
Posted by: DaveD | 28 April 2016 at 11:05 AM
They don't tell us what rate they did the long term cycling at. The 500 cycle graph looks good, if done at c/2, but if done at c/10 then no so much.
Posted by: Brotherkenny4 | 28 April 2016 at 12:30 PM
500 cycles is not referred to capacity under 80%. They just mentioned the cell was tested for 500 cycles and capacity loss was ok.
There is also the question of how much cycles do yo need. That depends on battery capacity; 500 cycles on a 60 kwh battery means more than 100k miles.
This technology is fascinating, but does not seem fit for production (3d graphene?). We need to develop nanoengineering to mass produce this kind of devices.
But at least we get a glimpse about what is possible using common chemistries, when you can order the molecules at your will. :)
Posted by: peskanov | 28 April 2016 at 12:36 PM
The path to reducing air pollution is not a choice between battery ice gas or fuel cell, all of them will still be around in 20yrs. its whats piratical. The tax at fuel pump and licencing by state will steer the market toward ride sharing electric auto steering with short range batteries with supplemental fuel cell or very small generators. One tech can not totaly take over, even apple could not take over the mobile phones. Checkout their project Titan. Driving will be for more sport, the robots will drive us safer and cheaper.
Posted by: solarsurfer | 28 April 2016 at 12:56 PM
My early prediction was GOOD WEATHER 500 Km BEVs by 2020 or so. TESLA Models S-100 or S-110 will do that by 2020.
My revised prediction for ALL WEATHER 500 Km BEVs is more like 2025. TESLA Model S-120 to S-140 may very well do about that by 2025.
Meanwhile, half a dozen or more FCEVs will do 500 Km in all weather conditions by 2020-2022. The problem may be more with the availability of enough low cost clean H2 stations. Germany, Denmark, Norway, Japan, UK, California and a few other west coast States and countries will have thin H2 network in operation by 2020-2022.
Posted by: HarveyD | 28 April 2016 at 01:48 PM
@ Dave D:
A certain gentleman will Make America (USA) Great Again starting in early 2017?
If he finds ways to repatriate 40% to 50% of the $XXT hidden away into 20+ 'Tax Heavens' or 'Tax Paradises' and ways to make it economically viable for manufacturers to return to USA to produce enough goods for local consumption, he will succeed?
Certain Trade Treaties may have to be modified or put on temporary HOLD. That's doable.
Posted by: HarveyD | 28 April 2016 at 02:06 PM
Dear gor, gas cars not subsidized? The oil industry is one of the most subsidized. Has been for 100 years despite profitability. Just the costs to the health system caused by fossil fuel use is huge. The fossil age has come and gone. The green age is upon us. :-)
Posted by: Paroway | 28 April 2016 at 02:18 PM
The rate of discharge of 0.27A g-1 for a battery with a capacity of 0.620 Ah g-1 implies a C/2.3 discharge rate. For a 60 mph average speed, this rate is faster than an EV with a 200 mile range (C/3.3) or a 500 mile range (C/8.3). So, 0.27A g-1 is a conservative cycle test value for use in EVs with a 200 to 500 mile range.
At 0.028% capacity loss per cycle (99.972% capacity retention per cycle), the battery would be down to 90 %, 85% and 80% of initial capacity after 376, 580 and 797 cycles, respectively. Using 80% capacity as the end of life for battery packs, the drop in capacity is linear enough to use 90% of initial capacity as the average capacity over the battery’s life. Then, on their original battery packs, a 200 mile EV would travel over 140,000 (= 180 x 797) miles on its initial battery pack and a 500 mile EV, almost 360,000 miles.
A promising chemistry; now for manufacturability, calendar life and other realities ….
Posted by: NorthernPiker | 28 April 2016 at 03:06 PM
Scribbling on another envelope....
Different sources claim the Tesla Model S battery weighs either 1200 lb or 1323 lb (600 kg). At 600 kg and assuming 85 kWh, that's 142 Wh/kg.
This battery has MORE THAN 8 TIMES that much capacity (down to ~7x at 500+ cycles).
Assume 1050 Wh/kg. Take 50% overhead for packaging (700 Wh/kg). Cut the weight in half. You've still got 300 kg * .7 kWh/kg = 210 kWh, more than TWICE the biggest battery option Tesla offers.
Unless there is some temperature sensitivity or other show-stopper that prevents automotive use, this battery has what it takes to kill the ICE.
Posted by: Engineer-Poet | 28 April 2016 at 04:01 PM
Engineer-poet, Evs will not kill the ice by a better battery but by a better overall package of accesibility to recharge slowly at home because many many drivers park in the streets or in common parking lot for renters and for accesible fast chargers while on the run. This will be necessary to clean and double the overall power of the grid but the problem is pollution and costs from natural gas and coal and every trucks, airplanes train and machineries cannot cope with even a 5x miracle battery.
Posted by: gorr | 28 April 2016 at 05:54 PM
gor, the only reason that there are gas stations everywhere but not charging at all parking spots is because most vehicles are ICE. By the time PEVs are 10% of the fleet, charging will be everywhere.
Posted by: Engineer-Poet | 28 April 2016 at 06:33 PM
Oh God, Harvey....please don't remind me of that orange skinned, bloated sack of pus with the bad hair.
Posted by: DaveD | 28 April 2016 at 07:37 PM
You mean the only front-running candidate who's against more wars in the Middle East?
Posted by: Engineer-Poet | 28 April 2016 at 07:46 PM
The annual US electricity consumption is about 3,900 TWh. Conversion of all US transportation to electrical power would increase US consumption by less than 1,700 TWh, 59% of which would be for light duty vehicles (cars, pick-ups, van and SUVs) and 22% for medium/heavy trucks, or less than 1,000 and 400 TWh, respectively.
Once this conversion begins, EV charging stations, both public and private, will increase in number and features - charge rate, contact/magnetic coupling, portable (road-side assistance), hours, etc.
Posted by: NorthernPiker | 29 April 2016 at 09:47 AM
You came up with figures almost identical to ones I calculated 12 years ago. How little some things change.
Posted by: Engineer-Poet | 29 April 2016 at 10:12 AM
So far, the numbers look good for energy density and cycle life, however, no data on power density. No data on maximum C-rating for discharge and charging. Need to be capable of at least 1C for discharge in a BEV having 100 kWh pack, and 1C charging rate for fast charging. If not, then not suitable for automotive application.
Posted by: Roger Pham | 30 April 2016 at 04:02 PM
Graph (b) shows a capacity on the order of 600-650 mAh/g, and (d) shows capacity at 2.7 A/g, implying at least 4C capability.
I'd settle for 2C. 2C charging with a 500-mile battery is 1000 MPH charging, and charging-in-motion at even 1C would be sufficient for all-day cruising (800 miles in a day requires 300 miles of CIM, or 36 minutes of charging in 10 hours more or less).
Posted by: Engineer-Poet | 30 April 2016 at 08:10 PM