Liquid air energy storage (LAES) is a class of thermo-mechanical energy storage that uses the thermal potential stored in a tank of cryogenic fluid. The research and development of the LAES cycle began in 1977 with theoretical work at Newcastle University, was further developed by Hitachi in the 1990s and culminated in the building of the first pilot demonstration plant by Highview Power Storage in 2010. The article will describe optimizing the thermodynamic principles of the cycle to deliver improve round trip efficiency, reduce cost and harness waste heat. The use of cold recycle is essential to deliver an efficient LAES cycle. The article will describe the necessary methods. The article concludes with the prospects of LAES for large scale deployment and integration with other power generation and industrial processes.