Should I inform other project's members about my work on an idea which they are not initially interested in I'm a PhD student working on a research project consisting of 2 teams. My team (team A) is on the practical side, we provide the problems related to our research and evaluate the theoretical solutions provided by the other team (team B).

Few months ago, I had an idea related to the work of team B and thought it would help to improve the quality of our research. I raised it during our project meeting but everyone was not interested and decided not to pursue it further. So, I decided to do it by myself. As the research was not in my supervisor's research interest as well, he did not pay much attention to it but still encouraged me to do it and publish a paper if possible. I occasionally gave him a brief progress update.

My effort paid off. I manage to publish a paper (in which I am the only author) and am planning to apply it into the project. At the recent meeting, members of team B were furious and accused me of bad teamwork as I did not inform them while working on something related to the project, especially when the idea belonged to their work, not mine.

I wonder if they are right and I should inform them my research, even though they were not interested at the beginning.
Congratulations on publishing a paper in the face of a lack of initial interest from Team B and your supervisor. That shows valuable tenacity.

I think, however, that you should have informed Team B as your work progressed, and certainly before publication. It is quite likely that you would have convinced members of Team B of the value of your work over time, and perhaps been able to involve one or more of Team B in your research. 

From Team B's perspective, you have encroached on their territory, and published a paper which perhaps they feel they should have had a hand in (read: been co-authors of). Keeping all your team members informed of your work is good practice. Whether they should have been included as co-authors on your paper is a matter of your own publication policies. 

Did Team A know about your work?