Explosion-proof battery
We are surrounded by lithium. Lithium battery is a standard for mobile phones, computers and electric cars; If bo force "energy wall" predict the future of beauty, lithium battery will become the core of modern home life.
"Lithium battery" three words, however, actually covers a variety of technologies, their difference is great. The Chinese academy of sciences, said David li Chen mast, a researcher of suzhou generally familiar lithium batteries, is actually "lithium ion battery. It with lithium ion embedded in the positive and negative and out electrical power and mutual transformation of chemical energy, so as to realize the charging and discharging process.
According to anode materials are different, can tell a lot of kinds of lithium-ion batteries. David li Chen mast said, at present the main use cobalt acid lithium cell phone battery anode and ternary material, the cathode using graphite materials. When charging, the anode in the lithium ion through movement to graphite anode, electrolyte and embedded graphite layers; Discharging, graphite layer lithium ion of emergence, through the electrolyte movement back to the anode material. Is, the greater the anode material of lithium storage capacity, lithium, lithium embedded potential difference, the greater the battery and the higher energy density.
"Bo force battery of beauty, the positive use lithium nickel and cobalt aluminate (NCA)." David li Chen said mast. In addition, the lithium ion battery anode materials and cobalt acid lithium, three yuan, manganese acid lithium, lithium iron phosphate, etc. Domestic battery giant byd, the electric car use mainly lithium iron phosphate anode material.
David li Chen said mast, due to the specific capacity is close to the cathode materials given twice as the anode material, therefore higher specific capacity of anode materials is the bottleneck factor in lithium ion battery to improve the energy density. Although lithium ion battery energy density, high and low temperature properties, ratio and many other performance indicators, performance is much higher than traditional lead-acid battery, nickel metal hydride batteries and other secondary battery, but its energy density and speed of the improvement of the performance of the cycle life of still difficult to meet the rapid growth of consumer electronics, electric vehicles, power grid energy storage, such as demand from emerging industry development.
In order to further improve the performance of the battery in the research of lithium ion batteries, the world there are a number of research institutions and business the company is committed to a new type of lithium battery. Lithium sulfur batteries, such as David li Chen mast research is the use of sulfur in the anode, lithium metal anode (lithium battery) in a strict sense, the weight energy density higher than that of the existing lithium ion battery is expected to more than 1 times. In addition, the research focus of lithium-ion batteries included lithium air batteries, as well as the use of solid electrolyte solid-state lithium battery.
"These new battery if for practical application, the energy density of the battery can get bigger promotion, promote consumer electronics, new energy vehicles, energy storage in the areas of development, high yield, but also there is a big risk." , "said David li Chen mast often have" DEMO "version of the new battery, but even the results published in top journals, has also had a lot in the process of the engineering of" land mines ", want success application there are a lot of difficulties, the media tend to exaggerate the performance of the new battery, too optimistic to new technology. ""Industry to improve the performance of lithium ion battery research and development, mainly on the basis of the mature system, according to different application requirements, specifically by the material body doping, surface coating, electrode structure design, the electrolyte formula, methods of process control, gradually improve its performance, some minimize side effects at the same time, to ensure product safety, reliability, the industry generally are gradually improve in this way." David li Chen said mast.
At present, the technology level of our country lags behind that of South Korea, Japan, ahead of Europe and the United States, the past is mainly medium and low-end market, but with the increase of our country enterprise investment, advancing to the high-end market. "But," said David li Chen mast, "because our country enterprise in production management, process control, production automation still has certain gap with Japan, South Korea, so need further effort. Japan battery production line, for example, there are about 200 or so of quality control points, the entire production process in a humidity controlled environment, the greatest degree to avoid the influence of moisture, and battery production enterprises in our country under the influence of cost, condition, quality control points only 20 or so commonly, good enterprise to reach 50, the degree of control and the larger gap."
In addition, due to the lithium battery industry in China due to excessive investment, overcapacity, causing severe price competition between enterprises, lithium battery product quality caused by uneven, even there are some low quality of the battery even old batteries into the market, such as "in less than a few times to deliver filling words fee, charge treasure", said David li Chen mast.
In spite of this, David li Chen mast for lithium battery industry in China still optimistic. He thinks, at present our country already has more than a dozen big businesses builders of doing research and development, the investment is also stable. In addition, the Chinese academy of sciences established the pilot projects, as a special group, said David li Chen mast, based on the requirement of the electric vehicles application of traction, the Chinese academy of sciences focus on the industrialization of high performance power lithium batteries, rather than the paper indexes, it is more likely to allow scientists to research into the benefit of the high technology products of the national economy.
