li has highest hydration energy of lithium ion among alkali metals thats why lithium is strong reducing agent. The heat energy released when new bonds are made between the ions and water molecules is known as the hydration enthalpy of the ion. read more
When something is oxidized, it reduces another substance, becoming a reducing agent. Hence lithium is the strongest reducing agent. Therefore Lithium is one of the most strongest reducing agent. read more
(-1) Saying that "lithium is a stronger reducing agent because it has a higher reduction potential" is just like saying "fluorine is reactive because it reacts with a lot of species readily". It's a tautology. read more