NiMH Batteries are pretty useful, but I feel like they tend to die out, which is a real shame in my opinion. The primary use of these cells are small electronic devices and flashlights. But these days more and more devices are sold with integrated Li-ion batteries for obvious reasons:
- They are cheaper to manufacture
- Li-ions are easier to charge
- The energy density is higher (NiMH: 140–300 Wh/L vs. Li-ion: 250–676 Wh/L according to Wikipedia)
- Low quality Li-ion batteries are likely able to withstand more cycles than their NiMH counterpart
- When the Battery is dead, many people will buy a new product instead of just replacing the battery
1. Do you think Li-ion batteries are going to replace NiMH ones entirely in the future?
2. I'm also wondering why NiMH batts were never used in energy storage systems (at least to my knowledge). Ni-Cd batteries were (and probably are) quite common in this kind of application.
High quality cells like eneloop don't suffer from high self-discharge rates. It's true that NiMH batts lower their charge efficiency when SoC is above 90% (according to AA Cycler http://aacycler.com/post/nimh-charge...gy-efficiency/) but a constant voltage charging algorithm that charges to about 90% SoC would eliminate this inefficiency and extend the battery's cycle life, as he has also shown (http://aacycler.com/post/charge-algorithm-comparison/).
So I don't see a reason why NiMh batteries aren't suitable for big energy storage applications. Cost maybe?
3. Does anyone know if Panasonic is going to continue researching NiMH-technology? Or are there other companies that do so?
Thank you very much for taking the time. And please correct me if I'm wrong with some points