Day: November 2, 2015

Lithium-Air Might Be The Better Battery

November 2, 2015 by 50 Comments

Researchers at Cambridge University demonstrated their latest version of what is being called the Lithium-Air battery. It can be more accurately referred to as a Lithium-Oxygen but Air sounds cooler.

The early estimates look pretty impressive with the energy density being 93% efficient which could be up to 10 times the energy density of Lithium-Ion and claims to be rechargeable up to 2,000 times.  Recent improvements toward Lithium-Air batteries include a graphene contact and using lithium hydroxide in place of lithium peroxide which increased both stability and efficiency.

Here’s the rub: Lithium-Air batteries are still years away from being ready for commercial use. There are still problems with the battery’s ability to charge and discharge (kind of a deal breaker if the battery won’t charge or discharge right?) There are still issues with safety, performance, efficiency, and the all too apparent need for pure oxygen.

Do batteries get you all charged up? Check out our coverage of MIT’s solid state battery research, or have a look at the Nissan Leaf and/or Tesla battery packs.

Thanks to [Jimmy] for the tip.

Magnetic Levitation With Arduino

November 2, 2015 by 7 Comments

Getting a magnetic field to balance on another magnetic field is about as easy as balancing a bowling ball on the tip of an ink pen. With a little help from an Arduino mega, however, [EmmaSong] was able to balance a high density neodymium magnet in midair. He pulled off this tricky project using a set of four coils he got off of Taobao (the Chinese version of eBay), a hall effect sensor, and a handful of current regulation ICs.

The coils can be made in house if necessary, with each winding getting about 800 turns of enameled wire. The rest of the circuit is straightforward. It appears he uses a potentiometer for a rough regulation of the current going to the coils, doing the fine tuning in the code which can be found here (.RAR direct download).

We’ve seen magnetic levitation here before, and this project adds to the list of successful techniques to accomplish this difficult project.

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