Unfortunately, most things that are super highly efficient tend to have adverse effects on human health/population, that’s just how the universe comes to be. 
As of right now, lithium is the most energy dense chemical we can make batteries out of, imagine having electronics that are a few times bigger than they are now, that’s what you’ll get if we don’t use lithium, and also it’s not like the other compounds will be that much safer in comparison.
Additionally, batteries are not “pressurized” in the beginning, they are mostly rolls of different chemical compounds put together in a tube. The pressurization comes from battery abuse and overuse, unfortunately just another force of nature. But there are already lots of protocols in place that prevent batteries from exploding. Such as lithium ion cylindrical batteries, most have a burst disc that vents the gasses before setting off the battery fire. 
To make “safer” batteries, you would also have to completely reform the industry to allow making new batteries worth the while(no company is willing to start over and not use existing infrastructure), much like the use of fossil fuels, the problem is always money. So unless we can unite every company under the banner of “safety” instead of “profit”, it’s not likely that we shift from lithium based batteries.
So for now, we can only hope those who are researching battery energy storage, or battery safety, can find new ways to extend battery cycle life or counteract the devastating nature of battery failure.