Researchers in China have developed a new Lithium-Sulfur (Li-S) battery that did not cause an explosion or fire, even after being cut. In fact, it continued to provide power after the damage. The team designed the battery with different layer structure in order to maintain safety and performance. 

The downside? The battery currently takes hours to charge. 

It has a ways to go before that can be commercially feasible as people are in a hurry to recharge their devices and get back on the go. But if the technology develops, or branches in a new direction that maintains safety while enhancing performance and lowering charge times, now we're onto something.