Earlier, a general scholar of fudan university has developed the so-called "water lithium battery", so-called energy density can be about 80% higher than a regular lithium battery. News released by the journal science reports, it has caused quite a stir in society, even make many people believe that a new round of revolution in the lithium battery has come, perhaps now is the best time to get rid of the dependence on oil. But in fact, the news is just a flash in the pan have not below, for more than two years have passed, we can't wait until that year professor wu also predicted water lithium battery electric vehicles. The way of scientific research will inevitably have a bumpy, failure is nothing once or twice. But it also bring another problem in front of us: what is the energy density of lithium battery, we can get rid of the dependence on petroleum energy? 

　　Speaking of which, the first thing we should popularize the concept of energy density. The so-called energy density, which is the energy per unit volume contains. If the energy density of lithium electricity increased 5 times, that is to say it in under the condition of same weight, contains power increased five times. International study of lithium batteries, actually also is mainly around the issue. Knows, engaged in the development of the battery energy density of lithium-ion batteries have been improved, but never get more than expected by leaps and bounds. For each big mobile power supply brand really can pull open price of key technical barriers, also mainly is the gap between the energy density. Security, intelligence, design, but is a foil. 

　　If the calorific value of gas conversion, that 46 million joules/kg of energy, can be converted to 3100 mah / 45 grams. And the same weight of li-ion battery device, reached only about 2.5% of the former. But considering the gasoline engine efficiency is very low, only about 25% when the fossil can be converted into kinetic energy, so an equal weight of li-ion battery can reach 10% of the energy petrol. In other words, if the energy density of lithium-ion battery technology today can increase 10 times, without considering the supply of ideally, piston engine cars in the history of mankind can all promote the history museum. And actually considering some problems in the economy, the energy density of lithium battery of 4 times the left and right sides, can preempt the fuel cars for the most part of the market. Just, now even the 80% promotion project ran aground, we really can't give four times this goal for a definite time.