Chapter 871 (2/2)
”Based on the ternary lithium battery used in mobile phones, lithium iron phosphate battery has been developed.”
”Lithium iron phosphate battery is a lithium-ion battery using lithium iron phosphate as positive material and carbon as negative material. The rated voltage of the monomer is 3.2V and the charging cut-off voltage is 3.6V ~ 3.65v.”
”During charging, some lithium ions in lithium iron phosphate are removed, transferred to the negative electrode through electrolyte and embedded into the negative carbon material; At the same time, electrons are released from the positive electrode and reach the negative electrode from the external circuit to maintain the balance of chemical reaction. In the process of discharge, the lithium ion comes out of the main pole and reaches the positive pole through the electrolyte. At the same time, the negative pole releases electrons and reaches the positive pole from the external circuit to provide energy for the outside world. ”
”Lithium iron phosphate battery has the advantages of high working voltage, high energy density, long cycle life, good safety performance, low self discharge rate and no memory effect.”
”If the traditional liquid battery is used, it needs one ton to meet the technical requirements of the U.S. military. Using lithium iron phosphate batteries, the weight will not exceed 50 kg. ”
Hearing this, everyone showed an incredible expression. What is this feeling that has directly pushed battery technology forward for 20 years or more.
David Bruce, the head of the assembly and an alumnus of baozixuan Massachusetts Institute of technology, asked, ”Dr. obrak, such a small volume and such a large energy density. How to ensure the safety? If it is directly fired by bullets or shells, will it bring disastrous consequences. At that time, the parachute incident during World War II will probably turn to black cloud. ”
This concern is normal. After all, they provide military products. Moreover, it provides products for the United States. If the safety performance is not guaranteed, there will be endless trouble.
If the battery explodes, such a large capacity density. The same mortar shell exploded. Isn't it very dangerous for the US military sitting on it. Because the product itself has problems, the whole enterprise, including the senior management of the group, will be severely punished at that time.
Moreover, the parachute story is true. The US military's requirements for military equipment can be said to be picky.
This is a true story between the US Air Force and parachute manufacturers in the middle of World War II. At that time, the safety of parachutes was not perfect, and the qualified rate was only about 60%. Through the efforts of manufacturers, the yield rate of parachutes produced by parachute manufacturers has reached 99.9%. It should be said that this yield rate is difficult for many enterprises to achieve even now.
But the U.S. Air Force said no to the company that they required the yield of parachutes to reach 100%. So the general manager of the parachute manufacturer went to the flight brigade to discuss the matter and see if this level could be reduced? Because the manufacturer believes that it is nearly perfect to reach this level, and there is no need to change it. Of course, the US Air Force refused because there was no discount on quality. Later, the military asked to change the method of quality inspection. That is to randomly select one of the parachutes delivered by the manufacturer the week before, and let the person in charge of the manufacturer equip himself and personally jump off the fuselage in flight. After the implementation of this method, the defect rate immediately becomes zero.
David Bruce worked in jeep before and developed and improved weapons for the U.S. military during the Vietnam War. It can be said that we have a better understanding of the U.S. military, put aside product performance, and safety is definitely the first. It's normal to raise questions, not for anyone, but for normal work discussion.
Obrak: ”you can rest assured about security; The electrochemical performance of the cathode material of lithium iron phosphate battery is relatively stable, which determines that it has a stable charge and discharge platform. Therefore, the structure of the battery will not change, burn and explode during the charge and discharge process, and it is still very safe even under special conditions such as short circuit, overcharge, extrusion, acupuncture and so on. ”
”Not only that, we will also wrap a layer of metal alloy on the outside of the battery shell. Unless it is directly attacked by guns with a caliber of more than 100mm, there will be no security problems. Even anti tank mines will not cause fatal damage to them. ”
”Although a certain weight will be added, the overall weight will be controlled within 80kg. With all kinds of auxiliary equipment, the overall weight of the power system will not exceed 100 kg, which can absolutely meet the requirements; Will not hold the whole project back. ”
Obarak has a double doctorate in physics and chemistry, and he is a famous teacher. He is the most demanding for technology, and his guarantee is very important. Don't say it represents authority, at least it can be convincing. If there are other doubts, they can only be verified by actual tests.
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