A major stumbling block in the development of a practical electric flying vehicle is battery technology, which is currently plagued by energy sources that weigh too much and produce too little power. This week, Boeing HorizonX Ventures' took a step into battery development for the aerospace giant, when it announced its first investment in an energy storage company, Berkeley California-based Cuberg.

The Berkeley startup was created by former Stanford University researchers developing next-generation battery technology for potential aerospace and industrial applications. Since it was founded nearly three years ago, Cuberg has developed an advanced battery cell designed as a dro-in solution to existing large-scale battery manufacturing processes. The Cuberg system combines a lithium metal anode, proprietary electrolyte and high-voltage cathode to achieve high energy density and thermal durability. Since April 2015, Cuberg has grown with several rounds of financing and grant funding and signed a multimillion-dollar joint development agreement with an industrial battery manufacturer.