VIEWS on BATTERY NEWS: TDK feels the heat. Aluminum cell material works in the lab. Concentrated solar finds cover.

TDK, the parent company of Amperex, has taken a hit to its stock after the Samsung Note 7 debacle. Amperex was the go-to supplier after Samsung determined their burning problem came from Samsung SDI. Amperex was already supplying a hefty percentage of the batteries for the Note 7.

But the problems with burning continued even after the Note 7 was replaced using the Amperex batteries. And now the Note 7 has been killed off. So TDK is also getting a great deal of fallout from the problem because their brand is tarnished and they are going to be sitting on a lot of stock that will have to be scrapped.




Aluminum as cell material has been very attractive to researchers because of its theoretical high energy density. But Al has so far been a poor performer in a cell because it seems to fall apart after a few cycles. But Prof. Tang of Shenzhen Institutes of Advanced Technology and his colleagues may have found a construction that stays together.

The idea was to allow the material to have some give to it by introducing holes in the metal and also coating it with carbon. The holes relieve mechanical stress and the carbon layer buffers the Al expansion and shields against undesirable reactions.

If this can get out of the lab and into production we can hope to see 2 times the capacity of our current best li-ion in production. Prof. Tang's lab tests held the test cell to a 2C rate, which is good but not as good as what we already have available. But in any case, we'll have to wait for some kind of production numbers before we can be sure what the capacity and current rate can be.

Insolight is a company that claims to have found an inexpensive way to utilize concentrated solar cells. The idea is to make the concentrator, and the machinery to direct the concentrator, simple and cheap.

They're using an injection molded lens right up near the ~40 percent efficient solar cells. This allows for a couple things. The concentrators can be at a heavy angle to the sun and still get the focal point onto the solar cell. And the second good point is that because of this extreme light bending the concentrator only has to move a few mm to get the full arc of the sun's rays.

But there are a few unanswered questions. We grant that this does not save space for the amount of energy generated. That's fine if the cost per watt generated is less. The real question comes up in maintenance and endurance costs.

Concentrated solar uses expensive solar cells that happen to also be a little more fragile than your standard ~12-15 percent efficient non-concentrated solar cells. And concentrating sunlight on them does their longevity no favors. But then having moving parts, even if they are simple low powered moving parts, are still a big maintenance cost if one has to go up and fix them. So it isn't just the up-front cost, but the ongoing maintenance and the replacement costs that need to have answers if this technology is to become a reality.