That is an XT__ connector for a lithium battery. They are commonly used for radio controlled toys like cars, planes, and drones. The single terminal connection is odd and is likely made for an unconventional special purpose.

These connectors are required for much higher current flow and voltages that multi cell lithium batteries are capable of producing.

There are many clones of the connector shown below and these do not have the same text as pictured. As far as I know, most clones are XT-60.