There are a couple of issues here:

1. In your render code, you are not calling this.superRender(). See https://developer.salesforce.com/docs/atlas.en-us.lightning.meta/lightning/js_renderers.htm

2. use xlink:href is not supported on IE

3. You have a cross site scripting vulnerability. Please either set this attribute to private or use setAttribute instead of innerHTML and sanitize the href to make sure you control the scheme to not be javascript

4. What is your re-render logic like?

There are a couple of issues here:

1. In your render code, you are not calling this.superRender(). See https://developer.salesforce.com/docs/atlas.en-us.lightning.meta/lightning/js_renderers.htm

2. use xlink:href is not supported on IE

3. You have a cross site scripting vulnerability. Please either set this attribute to private or use setAttribute instead of innerHTML and sanitize the href to make sure you control the scheme to not be javascript

4. What is your re-render logic like? (e.g. if someone changes the attribute then you probably want to load a new icon, but the current code doesn't do that)