Can I publish research as "working paper" after journal submission?
Most journal publishers have policies allowing you to release the manuscript that you have submitted to the journal (usually called the pre-print because it is pre-peer review) as long as you meet some requirements. Requirements vary by publisher, but commonly include only being able to put your manuscript on certain web sites and having to add a note to the manuscript saying it has been submitted to that journal. 

You can find the policy that applies to the journal you've submitted to by searching for 'pre print policy' or similar on their website. You could also look at a website such as Sherpa Romeo, which act as a searchable database of different journals' policies.