For the first time, a research group successfully uses eggshells as an electrode for energy storage
Biowaste in the form of chicken egg shells proves to be very effective for energy storage. In the journal Dalton Transactions, of the Royal Society of Chemistry, scientists present the sustainable storage material that could make a low-cost lithium ion capacitor possible.
Chicken eggs are used worldwide in large quantities in the food, pharmaceutical, and manufacturing industries, and for household purposes. However, after the egg is used, the shells are discarded and disposed of as bio-waste in landfills. The shell consists of a composite of calcium carbonate (CaCO3) and a protein-rich fibre membrane. “Surprisingly, there are always new examples in which natural substances have good to very good prerequisites for producing materials for electrochemical storage,” explains Professor Maximilian Fichtner from the Helmholtz Institute Ulm, a KIT-supported institution.
Together with his Australian colleagues, Fichtner discovered the promising electrochemical properties of chicken egg shells, which are able to store lithium well due to their high CaCO3 rate. The fine eggshell powders are used as an electrode against a metallic lithium anode in a non-aqueous electrolyte. Thereon, the cell maintained an excellent capacitance retention of 92% over 1000 cycles. Both the calcified shell and the shell membranes, including the inner and outer membranes, were used from the egg shells. The researchers washed, oven dried and crushed the shells to a powder and obtained a conductive material.
Egg shell waste has been used in a number of applications, including bioceramics, cosmetics and the dye industry. At the same time, the protein-rich, fibrous egg shell membrane has functioned as a separator in supercapacitors. Biowaste has now been used as an electrode for the first time worldwide. Further research and a detailed understanding of the electrochemical and physical behaviour of the material is needed in order to improve its performance and to enable its widespread use.
Bio-waste chicken eggshells to store energy.
Minakshi, M.; Visbal, H.; Mitchell, D. R. G.; Fichtner, M.
2018. Dalton transactions, 2018 (47), 16828–16834. doi:10.1039/c8dt03252a
Seven Canadian scientists from the field of energy storage visited the HIU on their European tour. Prof. Stefano Passerini, Director of the HIU, introduced the HIU research activities before giving a tour through the chemistry and physics laboratories. Prof. Joachim Ankerhold, Vice President of the Ulm University and member of the HIU board of directors, welcomed the researchers at the Ulm University with an overview of the science park on the Eselsberg. Prof. Axel Groß also presented the new POLiS cluster of excellence. Further stations of the delegation trip were the KIT and the ZSW – also partner institutions of the HIU.
The Canadian scientists belong to the NEST Network (Energy Storage Technology Network), which brings together researchers in Canada to develop next-generation energy storage technologies. The researchers, who belong to Ryerson University, École Polytechnique de Montréal, University of Waterloo, University of Ottawa and Simon Fraser University, visited several European institutions to explore collaborations within research projects.
Ten girls from the 8th grade used this year’s Girls’ Day on 28 March to take a look behind the scenes at HIU and got to know the work of a battery researcher.
Prof. Stefano Passerini, Director of the Helmholtz Institute Ulm, has now been elected to the Leopoldina, the National Academy of Sciences. Prof. Passerini has been working on the development of materials and systems for electrochemical energy storage for 30 years. His research focuses on the basic understanding and development of materials for lithium batteries, such as ionic liquids, polymer electrolytes and electrode materials. Passerini is the co-author of over 500 publications and for the third year in a row one of the most cited researchers in his field.
The Leopoldina is one of the oldest science academies in the world. Since its foundation in 1652, it is obligated to the advancement of free science, to benefit humankind and to shape a common future. With a base of about 1,500 members, the Leopoldina unites the forces of outstanding scientists from Germany, Austria, Switzerland and numerous other countries. The Leopoldina was appointed the German National Academy of Sciences in 2008. In this capacity, it represents the German scientific community in international committees and assumes a nonpartisan scientific position on social and political issues.
Professor Dr. Maximilian Fichtner reported on the current situation in energy supply at KIT’s Open Day. The focus was on the contribution that batteries can make to the storage of renewable energies and the challenges that have to be mastered in order to implement the energy system transformation in the coming years.
Learning tractors, synthetic CO2-neutral fuels, new technologies for e-mobility, innovative vehicle and transport systems. In addition, there was a knowledge rally for children and a top-class stage programme. KIT presented all this at the Open Day on Saturday, 29 June 2019, which also marked the start of this year’s EFFEKTE science festival in Karlsruhe. 9,000 visitors plunged into the exciting world of science at KIT’s Campus East with hands-on activities, lectures and demonstrations.
Dr. Heribert Wilhelm, Managing Director of HIU, welcomed the 20-strong delegation from Taiwanese representatives from industry, research and administration and informed them about HIU research, the research platform CELEST and the Cluster of Excellence POLiS. Baden-Württemberg International, the economic development agency of the state of Baden-Württemberg, carried out the information trip on the subject of battery-operated traction systems and charging infrastructure, a project of the BMWi’s Energy Export Initiative.
The information trip consisted of visits to German companies and institutions with the aim of informing Taiwanese decision-makers about German technologies and solutions and sensitizing them to their performance. At the same time, the information trip offered a forum for mutual exchange that could facilitate future cooperation.
Energy transition topics are gaining more and more political significance. The discussion about sustainable energy production and reliable supply security often leads to the question: Where could future energy storage systems be deployed and how do they have to perform?
How such a future szenario might look like was debated on September 16th, 2019 by numerous industry representatives at the Helmholtz Institute Ulm (HIU). The energy experts met for the events series “Energy Transition Dialogue” to catch up on current research results of electrochemical energy storage.
Rudolf Scharping, once Prime Minister of the State of Rhineland-Palatinate and Federal Defense Minister of Germany, led the accompanying workshop “Key to Energy Transition – Storage Technologies in Comparison”.
Prof. Dr. med. Maximilian Fichtner, Deputy Director of the Helmholtz Institute Ulm accompanied the workshop scientifically and provided an overview of current research results on electrochemical energy storage.
Scientists at Helmholtz Institute Ulm developed first electrolytes for calcium batteries with acceptable properties at room temperature.
Calcium-based batteries promise to reach a high energy density at low manufacturing costs. This lab-scale technology has the potential for replacing lithium-ion technology in future energy storage systems. Using the electrolytes available, however, it has been impossible so far to charge calcium batteries at room temperature. In the Energy & Environmental Science journal, researchers of HIU now present a promising electrolyte class, with which this will be possible.
Efficient, large, and low-cost energy storage systems will facilitate the transition to zero-emission mobility and power supply nationwide. Today’s predominant lithium-ion technology, however, cannot fulfill this task on a global scale, says Professor Maximilian Fichtner, Director of the research platform CELEST (Center for Electrochemical Energy Storage Ulm & Karlsruhe). Here, calcium batteries and other storage technologies are studied. “In the medium term, lithium-ion batteries will reach their limits in terms of performance and some of the resources used for their manufacture. This will prevent their future use wherever that would be reasonable for the energy transition. Availability of resources needed for manufacture, such as cobalt, nickel, and lithium, is limited.”
At the Helmholtz Institute Ulm Fichtner and his team focus on alternative battery technologies instead. These technologies are based on more abundant resources. Calcium is a promising candidate, because it can release and accept two electrons per atom contrary to lithium and because it supplies a voltage similar to that of lithium: “Calcium is the fifth most abundant element in the earth’s crust. It is distributed homogeneously on earth and it is safe, non-toxic and inexpensive.”
Search for a Suitable Electrolyte
Still, there has been a big obstacle in calcium battery development so far: In contrast to the established lithium-ion technology or more recent sodium or magnesium technologies, practicable electrolytes to produce rechargeable calcium batteries have been lacking so far. “For a few years now, experimental electrolytes and, hence, prototypes of the calcium battery have been available,” says Dr. Zhenyou Li, first author of the study, and Dr. Zhirong Zhao-Karger, who heads the project. Both are working in the POLiS (Post Lithium Storage) Cluster of Excellence at HIU.
“But these electrolytes enable charging at temperatures beyond 75 degrees Celsius only and additionally they are susceptible to undesired side reactions. ”The researchers have now succeeded in synthesizing a class of new electrolytes based on special organic calcium salts. These electrolytes enable charging at room temperature. Using the new electrolyte calcium tetrakis[hexafluoroisopropyloxy] borate, the researchers demonstrated feasibility of calcium batteries of high energy density, storage capacity, and quick-charging capability. Their results are reported in the journal “Energy & Environmental Science”.
Calcium Batteries as Sustainable Energy Storage Systems
The new class of electrolytes is an important basis for transferring calcium batteries from the laboratory to application. In electric vehicles, mobile electronic devices, and stationary storage systems, they might replace the presently predominating lithium-ion battery one day. But this may take a while: “The new electrolytes are a first important step,” Fichtner emphasizes. “There still is a far way to go to the mature calcium battery.”
Zhenyou Li, Olaf Fuhr, Maximilian Fichtner, Zhirong Zhao-Karger: Towards stable and efficient electrolytes for room-temperature rechargeable calcium batteries. Energy & Environmental Science, 2019. DOI: 10.1039/c9ee01699f.
Professor Horst Hahn, HIU founding director and director of the Institute for Nanotechnology at KIT, was elected a fellow of the National Academy of Inventors (NAI) in the USA. He will receive the award in April 2020 at the NAI Annual Meeting in Phoenix, Arizona.
Horst Hahn’s research in the field of materials science includes the synthesis of nanomaterials and nanostructures as well as their characterization and properties. In addition to basic research, he also focuses on application-related topics such as new battery materials, materials for printable electronics and nanomaterials for catalysis.
The National Academy of Inventors was founded in 2010 along the lines of the National Academy of the United States. The approximately 4,000 international members of the organization, including 1060 elected fellows, come from more than 250 institutions worldwide. The Fellow program honors academic researchers who, through their outstanding inventions, have a “noticeable impact on quality of life, economic development and the well-being of society”. Admission to the NAI’s Fellow program is the highest professional award for academic inventors.
“How do I charge my cell phone battery most gently?”, “How does the fire brigade extinguish the fire of an electric car?”, “What does the energy transition have to do with batteries at all?”
These and other questions 60 high school students asked three HIU PhD students on February 18, 2020. Two tenth grades of the Johann Vanotti High School in Ehingen were hosted guests at the Helmholtz Institute Ulm (HIU) to learn about new batteries and battery concepts.
Managing Director of the Helmholtz Institute Ulm, Dr. Heribert Wilhelm opened the visit with a short lecture on “the Role of Batteries in times of Climate Change”. Afterwards, the three HIU PhD students Linda Bolay (DLR), Mathias Künzel and Dominik Steinle answered questions from the students.
Why battery research?
Because it is not always available for immediate use, energy from renewable resources such as the wind and sun needs to be stored. Similarly, electric cars need intermediate storage of the electrical energy required for driving. Offering an efficient solution to this problem are batteries that temporarily store and release electrical energy with very little energy loss. The more lossless these batteries work, the more important their role in the energy transition.
Aim of the Helmholtz Institute Ulm
A student asks directly: “What is the long-term goal?” Well: The Helmholtz Institute Ulm (HIU) charges itself with the task of pursuing fundamental questions in electrochemical energy storage as a platform for creating vital new material and cell concepts. The primary aim of the HIU is to develop sustainable, next-generation battery technologies, in full, to develop electrochemical energy storage with more capacity and greater efficiency that is at the same time lighter, longer lasting, safer and cheaper than conventional technologies.
After the lectures and workshops, the 60 high school students were allowed to visit the institute’s physics and chemistry laboratories. Here they were able to experience what everyday life looks like for a battery researcher.
Invitation: For a day battery researcher
Girls’ Day: March 26, 2020
Would you also like to get a taste of the profession of a battery researcher? The Helmholtz Institute Ulm (HIU) offers regular insights into its interior. Around 120 physicists and chemists at HIU are researching future batteries for electric cars, laptops and smartphones.
In their laboratories, they show exactly how they do this: workshop participants are allowed to build their own batteries and work on glove boxes under protective gas. Visitors can examine various materials on a scanning electron microscope and take pictures of them.
The offer is aimed at students from grade 8 to 11. More information on this years’s Girls’ Day at Ulm University is available here:
March 26th, 2020
