Different from 360zip, 7z(18.05 x64 2018-04-30) only can extract one zip file to current folder or with the same name folder. When it comes multiple zip files, unzip file by file is not that efficient, so unzip_all.bat coms out.
Usage:
Put it under the same folder where all the zip files are and double click the ".bat" file to execute, and wait until the process finished.