Lithium Iron Phosphate cells can charge at a rate of up to 5C with no side effects - they're used in more expensive hand-tools and as primary power cells for electric radio control aircraft and helicopters.
That said, smartphones don't use these batteries, and anyone who tried to put a couple of amperes into a standard lithium polymer battery is going to have an amusing experience.
That said, smartphones don't use these batteries, and anyone who tried to put a couple of amperes into a standard lithium polymer battery is going to have an amusing experience.