Would you pass the battery exam?
Today I held the final exam in 'Energy Storage Systems' at Bochum University of Applied Science - and the students did a really good job! Would you pass the exam, too?
I picked ten of today's questions as a small brain teaser for my LinkedIn network - have fun! Feel free to answer and discuss in the comments.
1. What are the main ageing mechanisms of lithium-ion batteries in solar home storage systems? How can we extend battery lifetime?
2. Sodium-sulfur batteries have been widely used for grid storage applications such as load leveling in Japan and other countries. Why are they not used in electric vehicles?
3. A Spanish research group developed a new current collector design for li-ion batteries that promises a 50% lower ohmic resistance. Which applications will profit most of the new design? How can they market their innovation?
4. What is the main ageing mechanism of lithium-ion batteries when providing frequency control? How can we extend battery lifetime?
5. Nickel Metal Hydride batteries have been successfully used in hybrid cars like the Toyota Prius for many years. Today, some companies are trying to commercialize them for grid storage. What are the pros and cons of NiMH batteries compared to lithium-ion?
6. Some EVs use hybrid topologies that compromise 'high energy' and 'high power' storage systems. What storage systems are feasible for such an application and what are possible drawbacks?
7. How many km does the average person drive per day (in GER)? How many kWh of renewable electricity are needed to drive this distance depending on the power train of the car:
a) Battery Electric Vehicle
b) Hydrogen Fuel Cell
c) Synthetic Fuels
8. A typical example for latent heat storage is the pocket heater that is "charged" through boiling water and "discharged" over 2-3 hours. But latent heat storage can also be used to reduce carbon emissions of buildings - how?
9. Lead-Acid batteries have a extremely high recycling quoata in many countries worldwide. The recycling of lithium-ion batteries, on the other hand, needs to ramp up quickly in order to establish a ressource-efficient circular economy. Describe the two most common methods of recycling lithium-ion batteries and discuss their pros and cons.
10. What is a practical charging strategy for your smartphone to minimize ageing and still have enough Coulombs to carry you through the day?
Do you want to SHAPE the new energy world and DIFFERENTIATE with your Business? Consulting | Concepts | Implementation
4 年Interesting Idea to attract attention Dr. Kai-Philipp Kairies. I am Sure you will bring in after some days also the "official" answers, right? Another idea: Make an official Test of it where people can win a book or even better a Seat in one of your Seminars. When they answer everything right.
Driving revenue optimisation for grid scale BESS and Renewables | Business developer energy storage
5 年9) Li-ion battery recycling can be done using various methods ( several at early stage development).Two prominent methods are pyrometallurgical and hydrometallurgical processes. Pros of hydrometallurgical method is that it's used for primary and secondary Li-ion batteries and it's safe. Cons of Pyrometallurgical process is that it's not a dedicated method for Li-ion battery recycling. Hence lithium is not recovered. However, Cobalt, Nickel and Iron are successfully recovered. Another method uses a combination of the above two processes. Again, Li is not recovered. Thanks to second life usage, Li-ion batteries are extensively collected, refurbished and used in Solar+storage solutions even before recycling.
Cell Engineering at Tesla
5 年10) Practical charging strategy for phone would be to perform fast charge till 85- 90% SOC and slow charging till 95. Should be good enough for the day. I do that for my mobile phone and it lasts my usage.
Cell Engineering at Tesla
5 年1) Common ageing mechanisms for Li Ión are: Anode ageing, degradation of active materials, calendar ageing, cycle ageing to name a few. It can be controlled or reduced by avoiding over-discharge or over charge, operating in the specified temperature range. Utilization of BMS to manage cell and pack performance. Modeling batteries using equations in advance to understand behavior and prediction of performance. 2) Sodium Sulphur batteries have higher operating temperature (300 C). For EVs, it would need a better thermal Management using cold plates and glycol coolant to the least which would add weight and also it could be hazardous for passengers in certain scenarios.