Environmental concerns over the use of fossil fuels and their resource constraints have spurred increasing interest of renewable energy, and the needs for energy storage from the renewable resources is getting rapidly increase. Na/$NiCl_2$ cell could be use electric vehicles as well as energy storage, because it has a high energy-efficiency, environmental-friendly, low cost. However, there remain several issues on improvement of materials, component, cell design, and process, to use in broad applications and to penetrate to market. This paper offers a comprehensive review on R&D status of the structure, chemistry, key materials, and cell design & manufacture for Na/$NiCl_2$ cells.