20 hrs Layover in Shanghai

My husband and I are coming back home to the Philippines this December and our flight going back to the Philippines has 20 hrs layover in Shanghai and our return flight has 9 hrs layover in Shanghai as well. Since we have time, I want to travel some parts of Shanghai near the airport. My main concern is I am just a permanent resident of USA, I’m not sure if I need to secure a transit visa if our stay in Shanghai is less than 24 hrs. I don’t worry about my husband since he is already a US Citizen, I know he can go out of the airport without a need of any visa.