Here is how to vertically align and element within a div. This works well if you are trying to vertically align and images as well.
//Here is your html:
//Here is your CSS:
ul li {display:inline-block;}
ul li img {position:relative; top:50%; transform: translateY(-50%)} // This is the section that makes it work
Source: http://zerosixthree.se/vertical-align-anything-with-just-3-lines-of-css/