My brother in law works for a company in Silicon Valley which designs battery packs for cars and motorcycles. He regularly travels to China where they are expanding a battery factory that will soon be larger than the Gigafactory. He is intimately involved in QA and states the quality of the batteries they get from this factory is as good as Panasonic, LG, etc.
China can and does make high quality batteries (and a lot of other stuff). I don't believe in a cultural trait of "quality". Japan made a lot of poor quality stuff just after the war but quickly gained a reputation for high quality. China will follow the same path.
I grew up in Monterey Park which had a large Japanese population when I was born and then we got a flood of Taiwanese ex-pats in the late 70s. When I moved away in the 80s the city was over 60% Asian.
In the 90s I was sent to Singapore on business and passed through Japan going both ways. Singapore also has a large Chinese population.
Both growing up and when traveling I noted differences in Japanese and Chinese culture. Japan did turn out a lot of junk after WWII, but they were learning how to make consumer goods. They started industrializing in the mid-1800s and probably hold the record for evolving from a Medieval society to a modern power. But until the end of WW II, most of their industry was focused on military and practical goods.
In my experience Japanese culture is self reinforced. Everyone is expected to behave a certain way and people are only let off leash at certain times. Getting drunk with your office mates is one of those times and Japanese businessmen are renown for their booze ups.
That was also a tradition in the Japanese military too. At officer parties they would try to drink one another under the table.
But the rest of the time people are supposed to be disciplined and do the honorable thing. There will always be people who cut corners and break the rules, but it is not as culturally tolerated in Japanese culture as it is in many others. That contributed to Japan's rather quick advance from a defeated nation to a world power. They had a bit of a leg up over other Asian nations as they were the only industrialized nation in Asia before the war and they were able to apply that to retooling after the war.
Materials were also very hard to come by after the war. A lot of industries had to make do with what they could get which were 2nd rate materials until at least the 60s. It took until the oil crisis of the mid-70s before most Americans noticed Japanese imports, but some Americans did become aware of them and learned to appreciate them in the late 60s.
My experience of Chinese culture is it doesn't have the same internal self discipline the Japanese have. There is sort of an impishness in the culture that people who get one over on others are kind of heroes.
I noticed it in the shops. Japanese owned shops in my home town were spic and span clean and tidy. Everything had it's place and anything that got in the wrong place was quickly put back. Chinese owned shops were kind of like a jumble sale. They often kind of tumbled out onto the sidewalk with goods out on the street in front of the shop. I noticed that same characteristic about shops in Singapore too. Especially at the shopping mall where the locals went. I had a friend who I knew from online (I later learned his father was well connected with the government) who took me around and showed me the Singapore the tourists don't usually see. At the mall where the locals shopped, I was not only the only white person there, but also the tallest. I got a lot of stares.
Singapore is very orderly because the government orders it, but they have stricter laws to keep things in order. The chewing gum ban is a famous one, but there are others too. I would talk with the cab drivers when I was there and when waiting for a traffic light someone was caught at a red light camera (there was a flash as the picture was taken). I mentioned that those cameras were controversial back in Washington State and he couldn't comprehend how traffic could work without them.
When the animals in the US were getting poisoned by melamine in animal food we had a discussion about it on another forum I'm on. A woman who grew up in mainland China but now lives in Switzerland was saying it was just accepted that you didn't know what was in your toothpaste and people died brushing their teeth. That sort of daily Russian roulette with common everyday products was just accepted as normal.
The guy I work for is both the technical lead on my project as well as doing most of the sales and tech support. (He's horribly overworked.) He goes to China a couple of times a year to do sales and training. His assessment of China is similar to mine. China is capable of very high quality at comparable prices to the rest of the world (give or take a little), but they are also capable of turning out utter junk and you have to be careful and make sure you are getting the quality goods. They will deliver if you're watching, or you're dealing with a company that has a long reputation for quality, but otherwise you could end up with junk.
As time goes on, there are more Chinese companies that realize a good reputation is golden and try to foster that. But the underlying culture is working against them. China is improving in quality, and they are still growing at a fairly fast rate (though it has slowed down and there is some smoke and mirrors like empty cities built to boost the numbers).
I expect that the cells your brother gets from China are probably only a little bit cheaper than those from other countries, if at all. If you shop around you can find very cheap Chinese li-ion batteries, and they probably won't last very long. To make li-ion batteries correctly, you can't cut corners and the process costs what it costs. It's a very capital intensive process that doesn't all that many workers. The machines are expensive and the process from raw materials to finished cell takes a while.
I wouldn't be surprised if Elon didn't look at what it would cost to build a GigaFactory in China and import all the batteries, but because it's the equipment, not the workers, distance to the final assembly plant (Fremont), vertical integration of the process in one place, and access to raw materials are the biggest factors. The American workers are paid more, but it makes little difference in the end.
