This presentation should be helpful: http://li3-angular.lithium-framework.com/
What you're planning is the way to go: Li3 expose a json api, and Angular handles your routes and views. Your URL scheme should follow REST principles.
- li3_resources will help you to build a RESTful api: https://github.com/nateabele/li3_resources
- Angular UI router should help you with your routes: https://github.com/angular-ui/ui-router