Engineers at the University of Pennsylvania have found a new way to build and package microbatteries that drastically improve energy and power density even at the smallest sizes. They developed a new kind of current collector and cathode that increases the fraction of materials that store energy while simultaneously serving as a protective shell. This reduces the need for non-conductive packaging that normally protects a battery’s sensitive internal chemicals.
It weighs the same as two grains of rice but has the energy density of a much larger, heavier battery.