Welcome to Android Central! If the phone was completely smashed and won't power on, you won't be able to retrieve the data with an iPad or anything else. Were you backing up or syncing your data regularly anywhere, like your Google account? Hopefully you had your contacts saved to your Google account, and not the local Phone account -- go to contacts.google.com on your browser to see if they're there. Also, if you had Google Photos automatic backup turned on, your photos would be visible at photos.google.com.
If you weren't backing up or syncing anywhere, then a forensic data recovery specialist might be able to help, but they'll charge a lot of money. Sorry!