Can 12v destroy a laptop instead of 11.1v
The voltage on the battery pack, really any rechargeable pack of any chemistry,  is a nominal voltage. With Lipo cells this is typically the 90% charged voltage. The fully charged voltage will quickly drop over time or under high load due to its internal ESR and voltage curve (check the datasheet). A Lipo will then stay at its nominal voltage for most of the charge before quickly dropping when discharged. A 1.5V alkaline battery in comparison has a fully charged voltage of 1.6x V to nominally discharged at 1.1V, and fully discharged are 0.6V. 1.0 to 0.6 volts will be super dead and need something like a Joule thief to get out. A fully charged Lipo is much higher than its stated 3.6, 3.7 or 3.8 volt markings.

That said, there is no way to know how tolerant your random laptop is to the slightly higher voltage. When the laptop fully charges the battery, it is using a dedicated Lipo charging system, a battery monitor or gas gauge, and knows when to cut it off. You do not seem to have done the same.

That said again though, 12v isn't much higher than 11.1V. 9% higher. It will likely be fine. The laptop would use a higher voltage to initiate charging anyway. But use it at your own risk.