2 in 1 battery / Battery and package

According to the surveys, world consumption of primary battery is about 35 billion. Different size electronic devices need matching size batteries. Size mismatch is one big problem when we use batteries. AAA battery and AA battery have same voltage output which means they can replace each other. But now people need to buy twice the number of batteries just because size mismatch. So we design a battery adapter made of recycle-paper that can change the size of AAA battery into the size AA battery.