Best lens for my Nikon 1 j4?

I need to increase the quality of my video because I'm shooting some slow mo videos (video quality goes down as I increase the frame rate). I want the best one for my budget. My budget is $150.

Changing the lens isn't going to help - you need more light.

A different lens won't do any good.

You need a different camera,
and for that your budget is a joke.
Try $2,000 and up for a proper full-featured camcorder.