in the development of a new material which allows lithium ions to transfer quickly at a safe temperature. the heating you get primarily. because your anode and cathode materials are not able to move . lithium ions fast enough and then the heating causes a whole series of degradation, - electrolyte decomposes, _ the cathode decomposes, giving off oxygen and that causes fires. but even having addressed this, there are still challenges for the fast charging of the thing many of us care about the most, our smartphones. years of miniaturising their subsequent growing screen sizes has made this more difficult. these limitations come from the components, so the wires and connectors, and are usually limited to five amps, that is what you have in most usb sockets so the usb—c has to go to its next generation. that can allow faster charging