VDDP power supply voltage range on pins VDDP1 and VDDP2 goes from 3.5V to 5.25V, so in theory is should work without a problem, however, there is a trick, SPL limits the supply current when the 5 V supply (VDDP) drops below the SPL threshold (4.2 V). Even if the receiver requests more power, SPL continues to limit the output power until the supply voltage recovers. SPL (and SPR) can be disabled by connecting the CNF1 pin directly to the CNF_IN pin. An application that operates from a 3.7 V battery source as in your case (e.g. low-power application for wearables) can be realized by disabling SPL. However, to protect the power supply, SPL is mandatory for a Qi certified application.