This subject may be common knowledge to many on this list, but I was unaware of it. I was wondering if the lithium in the batteries we all use could be replaced with sodium so I just did a web search (I, like many, no longer google) and found there has been considerable research going on in that direction.
Improvements in the structure of the "hard carbon" electrodes bodes well for the future of this type of battery. Besides using one of the most common elements on earth as opposed the far rarer lithium, it also won't need all of the expensive and potentially toxic heavier metals used in lithium ion batteries. You can just look up "sodium ion battery' in Wikipedia and there are all sorts of links for those who are interested.
