A minerals deal is a good thing, but a long way from peace.
I'm afraid the incentives to get Putin to agree a peace deal are not strong enough yet.
He is not responding to positive reinforcement. And right now he if he continues the fight, Russia is compensated with more and more Ukrainian territory.
The negative reinforcement for non-compliance is riskier, however. What can the West do (that they have not already done) to punish Russia for not signing a peace deal? The West has donated tens of billion of dollars worth of military aid and that has not stopped the gradual Russian advance. Send western troops to fight? Europe could stop buying Russian oil but others will buy it and getting oil from elsewhere will just cost more.
There are just limits to soft power (and semi-soft power like embargoes) can accomplish. At some point, hard power, as in military force, are needed and I am not sure anybody wants to send their troops to Ukraine to fight.