How old was Qin Shi Huangdi when he died and how did he died?

He died of disease when he was 50 years old.

He died of malaria

Shi Huang Di died of Mercury (the metal) by drinking it. He searched for an elixir of life. His workers thought that Mercury would do the work. He drank it at age 49 and died that very moment. His tomb has not been opened because he ordered Mercury to be filled by it, right before his death.

Qin shi huang is Chinese emperor lived 100Bc-210bc
The emperor who built Great Wall of china
But one thing I don't believe is he is not powerful than Japanese emperors

Are there any plans to open his tomb, if technology can help avoid the Mercury fumes?

thank you for that information oliver

Thanks Oliver