u can't find this battery on ebay ?
No, it's a 2017 model & the only place I've found it is Taobao
Dealing with Chinese industries 101
If that is the only place you can find it, I would highly recommend NOT buying it at all.
When that is the case, it's quite often that:
It was a reject and was liberated from the trash of said manufacturer, often with their knowledge (most Apple laptop batteries), and are claimed to be overstock (sometimes it is, but rarely). Sometimes there are even sold through shell companies of the company actually making the parts. For example, Apple's battery supplier, company A, sells the rejects to company B, a division of company A, who sells them off with authentic labels and all.
Or, it's a copy, often done with zero concern for quality because they know you will blame the original manufacturer (see the above regarding Apple batteries). Often these are made by companies who were going to manufacture that item but couldn't get the quality high enough and the company went elsewhere. So while they know the specs, they simply are not up to snuff.
A bit less common but also possible:
They don't actually have it and are fishing for buyers, if there is demand, then the above happens (not so common but does happen)
It was found after it "dropped off the back of a truck" (I.E. stolen from the factory), this is actually rare, but is often the only way you get a good part from a seller like this.
Regardless, very few of those are going to get you a quality product, and that is IF you ever even get it.