VOA慢速英语:US Inventor’s Battery Could Change the World… Again

commercially – adv. related to the buying and selling of goods

solid-state – adj. of or relating to the use of the electric or magnetic properties of solid materials

density - n. amount of something in a particular space or area

sustainable – adj. able to be used without being completely used up or destroyed

convenient – adj. easy to use

grid – n. system of electrical wires and equipment to supply electricity to a large area

range – n. a distance

fossil fuels – n. a fuel (such as coal, oil, or natural gas) that is formed in the earth from dead plants or animals​

intellectual property – n. something (such as an idea, invention, or process) that comes from a person's mind

breakthrough – n. a sudden development, especially one involving knowledge or a process