Our locker will have a phone charger and a refrigerator. It will be easily accessible, because it will have a keypad as opposed to the standard lock (which takes a long time if it gets jammed).
The purpose of a school locker is store things that you don't want or need to carry to your classes.
In elementary school, we had cubbies instead of lockers. The cubbies were used to hold our lunchboxes and art supplies. Now, we use our lockers as storage units for textbooks, phones, and clothes.
Personally, neither Drake nor myself have a locker because we prefer to carry our things. However, the people that we know who have lockers visit and open their lockers 4-5 times a day.
Teachers and school administrators do have security concerns about lockers. This is because most people leave their lockers open, because they don't want to take the time to unlock them. This makes it very easy for anybody to go in to somebody's locker and steal something.
When lockers were first made, they were made out of wood. Then, it was commonly made out of metal. As they continued to be innovated, they are now usually made with high density polyethylene. This is because it is a lighter, less noisy material.