Indeed, at least 2 Chinese companies (CATL and BYD) already have in mass production sodium-ion batteries, including a 50 MWh model for stationary storage.
Using lithium-ion batteries for stationary storage is a historical accident, because using lithium makes sense only in mobile applications where weight is essential.
For new installations, sustainable alternatives, like sodium-ion batteries, should be preferred.
In the past there have been many companies in various countries, including Australia, UK and USA, which have claimed that they are able to make very high capacity flow batteries for stationary storage, based on various chemistries, e.g. vanadium-vanadium or bromine-sulfur. A few such batteries have been installed at various customers.
I do not know what went wrong with flow batteries. They have bad weight, similar to the lead-acid batteries, but that is irrelevant for stationary batteries. Otherwise they should be the best batteries for stationary applications, because they have 3 essential advantages over other batteries. Their energy and their power are not coupled as in normal batteries, but they can be scaled independently, i.e. for a given power (which is determined by electrode area) in a flow battery the stored energy can be made arbitrarily large, because it is determined by the volume of a couple of tanks where liquid electrolytes are stored. The second advantage is that the auto-discharge when the battery is not used can be almost null, because the 2 electrolytes can be stored in separate tanks, preventing any reaction between them. The third advantage is that the solid electrodes do not take part in the chemical reaction, so they are not damaged by a charge/discharge cycle, so they can have a very long life.
Despite the advantages, none of the many kinds of flow batteries that have been proposed has been a commercial success and it appears that the companies producing them have lied about the problems that might plague them.
I have not seen any published information about which were their problems, but I assume that a likely cause was the separator membrane that stays between the 2 liquid electrolytes, which must selectively allow the passage of certain ions and not of others. Such membranes are expensive and they might have a short lifetime, requiring frequent maintenance. Another possible problem could be caused by secondary reactions leading to solid precipitates from the liquid electrolytes, another possible cause for expensive maintenance.
Regarding the battery firmware, it does not really matter if the batteries are made in China. The history of the last 3 decades has demonstrated that no firmware can be trusted, regardless whether it comes from a company located in USA, in UK, in China or in any other country, so any firmware must be treated with suspicion.
China actually makes a great number of electronic products that are much more trustworthy than almost anything that comes from USA or other western countries, because those products, like it was the norm several decades ago, but no longer today, are accompanied by full hardware documentation, including schematics and PCB layout, which makes it much easier to verify that a malicious firmware would not be able to do damage.
If the European Union or any other countries would be concerned by the security risk posed by malicious firmware, the solution is simple and it does not consist in banning the products of some arbitrarily chosen countries, but in mandating that any product with an embedded computer, regardless of its origin, must provide complete documentation, i.e. schematics and the source program for the firmware, and it should allow the replacement of the firmware. This would be nothing new, as this is how computers, including the IBM PC, were sold in the old times, before the vendors succeeded step by step to incline the balance of power in their favor and in the detriment of their customers.
