I am not sure to completely understand your problem, but as far as I know an Angular 2 library is nothing more but an Angular 2 application you import in another as a module using npm. For example ngx-translate.
These kind of modules have to be added to your app.module.ts file.
Angular 2 accepts non-specific Angular 2 modules as well, and you can require them in your app. For example if you want to use MomentJS, you can do :
npm i --save moment
And in your component or service or whatever:
import moment = require("moment");
So to create a library you can follow one of these schemes and nothing should run well.
If you use Webpack and want a library to be globally available (JQuery for example), you can require it in the vendor.ts file.