Why! For example, in a room with a certain volume, a person can only carry a bucket of water into the room (a bucket of water does not take up space). How can I fill more water? The answer is to take children to carry water, because children are small, and if more children can be held in the same room, more buckets can be held.
Why use lithium as a battery? Everyone recited the periodic table and chemical batteries. The largest number of atoms per kilogram (equivalent to a house) is lithium. Each lithium atom (each proton) provides a useful electron, and the electrode potential of lithium is high, so lithium is used as a battery. Everyone has thoroughly understood these basic theories. When Edison invented the lead battery, he thought of lithium. However, due to the technical conditions at that time, lithium was too active, the reaction was unstable, and the preparation amount of lithium was small, so he had to choose lead as the main material of chemical batteries.
However, chemical batteries must also have electrolyte. Although electrolyte is an auxiliary function, it is an essential substance. The process of electron transfer and utilization can only be completed with the participation of metal electrodes and electrolytes. Counting these, the energy density of chemical batteries has dropped a lot. Theoretically, the largest energy density is lithium air. Because theoretically it reacts with oxygen in the air to complete the process of electron transfer and utilization. Doesn't it use any electrolyte? No Moreover, lithium reacts with carbon dioxide and nitrogen in the air, and only oxygen cylinders can be used. The so-called lithium-air battery energy density can only reach per kilogram 1 kWh in the laboratory. By the way, there are also aluminum air batteries and magnesium air batteries, both of which are commercially available. The energy density of existing aluminum-air batteries is per kilogram 1 kwh. Why not use it in the car? Some people say that aluminum air is a disposable battery and cannot be recharged. That's not easy. Every city has an electrolytic aluminum plant, so it's good to be close. The key problem is that no one says that there are not as many batteries as people think, and they can put as many as they want. Another key indicator of the battery, power density, aluminum air and magnesium air are not high. If you want aluminum air to release the power that can drive electric vehicles, you have to put about 4 tons of aluminum air batteries in the car. Who wants a car like this? It's good to have100000 deposit in the bank. The bank only allows you to mention 10 yuan one day, hehe! By the way, atomic children can only carry one bucket of water, and aluminum children can carry three buckets, which is the basic reason why the theoretical energy density of aluminum air is second only to lithium air.
What if there is more coal, oil and combustible ice? Before the sun goes out, the greenhouse effect created by the chemical fuels used by human beings will kill themselves first.