Canvas is a learning management system that is also a great way to have students create e-portfolios. It has many of the same features as other LMSs as well as some unique ones. It has task management, reminders, calendars, audio and video messages, badges, chat, collaborative workspaces, course creation, discussions, a dashboard, mobile apps and much more.
Students can share their e-portfolio's too. Here a link to the Canvas Guides of a video (less than five minutes) walking students through setting up an ePortfolio. There are standard and closed captioned viewing options on this page. There is also a longer version which goes into details of how ePortfolios work, how to create them, why they're used, etc. here's a CanvasLive training on ePortfolios (52 minutes).