Tipps for Volibear vs Renekton?

Hi, my favourite champs atm is Volibear, but whenever I face Renekton I seem to struggle a bit.

Whenever he goes in, I fling him back, slow him, aa in between and bite right before he dashes away. however, he can usually outsustain me and my mana. Any advises what else I could do?

I run 9/21/0, ad reds, ar yellows, scaling mr blues and newly hp quints, starting with dorans shield. btw, gold V, not the best mechanics...