Energy created nor destroyed.

[Pyrrho]

Take a stick of dynamite.  Light the fuse.  Run away.  After the tremendous bang, go back and look for your stick of dynamite.

Boru

First of all that everything that comprised that stick of dynamite still exists, it's just in a different form. Matter and energy both have mass, which means if the dynamite was converted into energy, it still physically exists because energy has mass.

The stuff that makes up your mind still exists when you die, but it is no longer your mind, just as that apple you ate earlier was not a part of your mind before you ate it and your body processed it.

When you die, the chemical energy that your brain and body use simply dissipates. It is not destroyed, rather, it is passed on to the various small lifeforms that help our body decompose.

A battery supplies energy chemically, but when a battery "dies" it can be recharged, why can't you then do the same for a human body?

If a body has not fully died yet, a person can sometimes be resuscitated. But once the brain deteriorates too much, it cannot "hold a charge" (to use your battery metaphor). A battery, too, can be too degraded to be able to be recharged.