Kansas State University: 3D Freeze Printing Used to Create Batteries

3D design and printing can be integrated into nearly any industry today, but researchers around the world persist in using it to harness energy, and especially for storage—as in the ubiquitous battery. Researchers from Kansas State University examined previous studies and then delved into much more intricate research with an inkjet 3D printer using freeze casting to control materials for storing energy.

Numerous forays have been made into the study of 3D printing with electronics and the creation of batteries, but as the authors discuss in their recently published paper, ‘3D printing of hybrid MoS2-graphene aerogels as highly porous electrode materials for sodium ion battery anodes,’ previous work has been centered around more common materials like lithium iron phosphate (LFP) and lithium titanium oxide (LTO), along with 3D printing of disk electrodes and nanocrystal inks.

For this study, the researcher used a new technique for preparing highly porous MoS2/graphene hybrid aerogels as the anode for sodium ion batteries (SIBs).

“Such interconnected porous structures are critical in mitigating the stress induced by the larger volume changes during charge-discharge cycles than that in the previous LIB studies due to the combination of higher specific capacity (over 300 mAh/g) and larger ion size (0.102 nm for Na+ vs 0.076 nm for Li),” stated the researchers.

Schematics of the 3D “drop-on-demand” ink jet printing setup (a) and the printing process of the ATM-GO droplets in a raster fashion (b–c). Ice template formation (d) during printing and the resulting ATM-GO aerogel after freeze drying (e). An example macrostructure of the 3D printed ATM-GO aerogel after free-drying (f) and the resulting MoS2-rGO aerogel after reductive thermal annealing (g). (For interpretation of the references to color in this figure, the reader is referred to the web version of this article.)

Both graphene and molybdenum disulfide (MoS2) are known to have exceptional qualities, as 2D layered materials that have been well-studied already. There are challenges, as MoS2 is known to deteriorate rapidly, and electrical conductivity is low. Graphene compensates for any disadvantages there, however, with superior conductivity, flexibility, and chemical resistance.

Using a cold substrate plate, ink droplets are frozen during 3D printing, beginning the process for creating hybrid aerogel-based 3D architectures for batteries. Precursor ink was created as nanoflakes were placed in deionized water an then pressed onto the cold plate set at −30 °C. The droplets quickly froze into ice crystals and then formed a matrix, after which they were put into a freezer and later transferred to form the required aerogel and go through consequent refinements.

“The printed architectures were clearly retained after going through all these processes,” stated the researchers. “To the best of our knowledge, it is the first time to achieve 3D printing of MoS2-rGO hybrid aerogels.”

The authors of the study also note that the MoS2-rGO aerogel is much different from those created through more common methods in 3D printing and freeze-drying materials. They postulated that the open 3D Ni foam framework must have transformed the temperature, along with preventing large ice crystals from forming.

Low a) and high b) magnification SEM images of MoS2-rGO printed on Ni foam. EDS layered elemental mapping of c) all elements, d) sulfur (red), e) molybdenum (purple), f) carbon (green) and g) oxygen (blue). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Overall, the aerogels were successfully 3D printed with the freeze-printing technique, with the graphene network increasing conductivity and strength, while large pores make rapid ion transport possible.

“This study demonstrates the potential to use 3D printing technology to fabricate the macroporous electrode materials that can sustain high-capacity intercalation of large Na+ ions, which opens a new direction of 3D printing for energy storage applications,” concluded the researchers.

Energy is one of the most critical commodities on Earth, allowing us to perform many daily activities comfortably, and with many battery-driven machines and objects. Because the benefits of 3D printing so often include greater affordability, speed in production, and the ability to innovate like never before, researchers have looked into how it could improve battery manufacturing, from wearables to sensors to applications requiring materials like graphene. Find out more about hybrid MoS2-graphene aerogels in batteries here. What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

EDS spectrum of the MoS2-rGO aerogel on the nickel foam.

[Source / Images: ‘3D printing of hybrid MoS2-graphene aerogels as highly porous electrode materials for sodium ion battery anodes’]

Clemson Researchers Use 3D Printing to Solve Pesky Battery Issues By Printing Ceramic Electrolyzers

We’re all familiar with that highly inconvenient moment of finding out your phone battery is dead (or worse, that the charger cord or cube is no longer functional for some often, unknown reason) or that the electric car is running out of ‘juice.’ As progress in technology just continues to climb to higher levels, however, you may find that you can take control of battery power with 3D printing. And while that is not exactly a new concept, it is becoming even more realistic thanks to recent research from Clemson University.

A laser-based 3D printing process may be able to create energy—along with enormous amounts of storage. Jianhua “Joshua” Tong, associate professor of Materials Science and Engineering at Clemson, is behind the project, which streamlines the manufacturing of electrolyzers using devices made of ceramic material. Tong explains that their innovative devices could actually use hydrogen to harness and store solar—or even wind—energy and use it to power larger items like cars.

“Our success will mean we can provide sustainable, clean energy,” Tong said. “That is the fantastic part. We are taking 3D printing to the next level.”

This research involving 3D printing was performed at Clemson’s Department of Materials Science and Engineering, where Tong also worked with Hai Xiao, Kyle Brinkman and Fei Peng. Because manufacturing of ceramics for industrial use has historically been very expensive, their goal was to create a manufacturing process that is affordable and realistic for modern applications.

Their process makes use of some of the greatest benefits in 3D printing, including better savings on the bottom line and greater speed in production, mainly due to their bypassing the need for a furnace to produce the electrolyzer. This could be extremely useful in terms of making fuel, as well as offering new potential in the creation of other products such as smartphone batteries with the possibility to stay charged for several days. Considering most of us are running low on battery power by the end of the day (or even more quickly), such products could be a real boon to the smartphone/battery industry overall. Using protonic ceramic electrolyzer stacks the team can let hydrogen act as a fuel store for batteries. By sintering and depositing the different ceramics needed simultaneously the team can make these energy storage devices in a completely new way. This is yet another application where we can see 3D printing used to bring changes to batteries.

Jianhua “Joshua” Tong, left, and Ph.D. student Shenglong Mu work in their lab at Clemson University, where they are developing a new technology that combines 3D printing and laser processing. (Photo credit: Clemson University)

The researchers also found that 3D printing offered incredible ease in production because of the ability to create a 3D design that can be emailed to another individual or company getting ready to 3D print a component or prototype. 3D design also means that prototypes can be changed easily in digital fashion—rather than working with a middleman who must go back to the drawing board for most changes.

The use of 3D printing integrated with other processes such as electronics offers infinite opportunities for designers and engineers hoping to create more streamlined works for users around the world. Find out more about Materials Science & Engineering at Clemson here.

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[Source: Design News]

Researchers 3D Print a New Variety of Zinc Ion Battery Shapes for Wearable Devices

With the development of flexible wearable devices comes the need for new battery shapes, as most batteries are currently limited to spherical or rectangular shapes. These shapes do not use space as efficiently as other shapes could, so a team of researchers led by Professor Il-Doo Kim from the Department of Materials Science at KAIST and Professor Jennifer Lewis from the School of Engineering and Applied Sciences at Harvard University have used 3D printing to manufacture batteries with a variety of novel shapes.

These shapes include ring-type, H and U-shaped batteries. Through a research collaboration with Dr. Youngmin Choi at the Korea Research Institute of Chemical Technology (KRICT), these 3D printed batteries were applied to small wearable electronic devices, namely wearable light sensor rings.

The team adapted environmentally friendly aqueous Zn-ion batteries to make customized battery packs. The system, which uses Zn2+ instead of Li+ as charge carriers, is much safer than rechargeable lithium batteries, which use highly flammable organic electrolytes. The processing conditions of these lithium-ion batteries is also highly complicated, as organic solvents can ignite upon exposure to moisture and oxygen. The aqueous Zn-ion batteries are stable upon contact with atmospheric moisture and oxygen, so they can be fabricated in ambient air conditions. They also have advantages in packaging, since packaged plastic does not dissolve in water even when 3D printed.

The researchers used an electrospinning process to fabricate a carbon fiber current collector and uniformly coated electrochemically active polyaniline conductive polymer on the surface of the carbon fiber for a current collector-active layer integrated cathode. The cathode, which is based on conductive polyaniline consisting of a 3D structure, exhibits extremely fast charging speeds, with 50 percent of the charge being completed in two minutes. It can be fabricated without the detachment of active cathode materials, so various battery forms with high mechanical stability can be manufactured.

“Zn-ion batteries employing aqueous electrolytes have the advantage of fabrication under ambient conditions, so it is easy to fabricate the customized battery packs using 3D printing,” said Professor Kim.

The research was published in a paper entitled “High-Power Aqueous Zinc-Ion Batteries for Customized Electric Devices.

“3D-printed batteries can be easily applied for niche applications such as wearable, personalized, miniaturized micro-robots, and implantable medical devices or microelectronic storage devices with unique designs,” said Professor Lewis.

Most current battery shapes are optimized for coin cell or pouch cells. Since batteries occupy most of the space within microelectronic devices, different shapes are required to fit the new wider variety of devices. The researchers’ success could lead to more of a variety of wearable devices, including very small ones.

In related news, Professor Kim was appointed as an Associate Editor of ACS Nano, in which the article was recently published.

“It is my great honor to be an Associate Editor of the highly renowned journal ACS Nano, which has an impact factor reaching 13.709 with 134,596 citations as of 2017,” he said. “Through the editorial activities in the fields of energy, I will dedicate myself to improving the prominence of KAIST and expanding the scope of Korea’s science and technology. I will also contribute to carrying out more international collaborations with world-leading research groups.”

(L to R) Dr. Bok Yeop Ahn, Dr. Chanhoon Kim, Professor Il-Doo Kim and Professor Jennifer A. Lewis

Authors of the paper include Chanhoon Kim, Bok Yeop Ahn, Teng-Sing Wei, Yejin Jo, Sunho Jeong, Youngmin Choi, Ill-Do Kim and Jennifer A. Lewis.

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[Source/Images: KAIST]