“Battery cathode materials are developing towards high nickel, cobalt free and single crystal. In terms of electrolyte materials, solid electrolyte is the main research direction at present.” On April 28, at the 2022 “lithium battery city” industrial ecology and supply chain conference held in Shehong City, Sichuan Province, Wu Feng, academician of the Chinese Academy of engineering and chief professor of energy and environmental materials of Beijing University of technology, shared the research and Prospect of new green secondary batteries and their key materials.
According to Wu Feng, the energy density of lithium sulfur (li-s) battery developed by the scientific research team of Beijing University of technology has reached 651 watt hours / kg by building reaction, strengthening interface and inhibiting dendrite growth. The research results on the catalytic materials of high-performance lithium sulfur batteries were published in advanced materials, a top international journal of materials, in April this year.
At present, the energy density of lithium-ion batteries is about 260 watt hours / kg. Lithium sulfur battery has higher energy density, lower cost and stronger environmental protection than lithium-ion battery. However, due to its low rate performance, cycle life and safety, it is still a certain distance from commercialization.
In the research and development of a new generation of lithium-ion batteries, in order to break through the limit energy density of lithium-ion batteries, the scientific research team of Beijing University of science and technology introduced the coordinated charge compensation of anion and cation in the research of high-capacity cathode materials, making the transition from single electron reaction to multi electron reaction of traditional lithium-ion batteries. According to Wu Feng, the scientific research team is also studying a new battery system with both energy density and high power density to improve the functional characteristics of the battery through the regulation of electrode surface structure and interface function.
In terms of new material batteries, the specific capacity of aluminum ion cathode materials studied by the scientific research team of Beijing University of technology reaches 467 MAH per gram, which provides a material basis for improving the energy density of aluminum ion batteries. In addition, Wu Feng believes that at present, sodium ion batteries have opened up a new source of raw materials. Due to their rich raw materials and wide distribution, they have certain cost advantages and development potential.
In terms of battery safety, the scientific research team of Beijing University of technology has invented safety materials such as temperature sensitive electrode, ceramic high-strength diaphragm and safety electrolyte from the basic steps of regulating and cutting off electrode reaction. According to Wufeng, the new generation of gel solid electrolyte developed by the team has greatly improved its safety, and can remain incombustible for 60 seconds at a high temperature of 1300 ℃.
In addition, Wu Feng looked forward to the innovation of battery system from analog to digital. “We are developing smart batteries and smart battery systems, using semiconductor technology to prepare batteries. In the future, large chips will enter the battery. The emergence of smart batteries will subvert the structure of battery systems, further improve the safety of power batteries, and become an important link in the intellectualization of new energy vehicles,” he said
Wu Feng pointed out that material innovation, technological breakthrough, production capacity and cost are the common issues faced by China Shipbuilding Industry Group Power Co.Ltd(600482) battery enterprises.
At present, China has become the country with the highest production and sales of lithium batteries in the world. In 2021, the installed capacity of global power batteries increased by 102% year-on-year, and the total installed capacity of Chinese battery enterprises continued to rank first in the world. According to the white paper on China’s lithium battery industry development index released at the meeting, it is expected that the overall market scale of China’s lithium battery will reach 865gwh by 2025
In the process of realizing the goal of “double carbon”, the new secondary battery is the focus of international research and development. The United States, the European Union, Japan, South Korea and other developed countries have put forward the strategic development plan of high-performance battery. “Patent barriers in developed countries may cause the risk of neck sticking. We need to ensure that the core technology of high-performance batteries is independent and controllable.” Wu Feng said.
Academician Wu Feng has been engaged in the research and development of new secondary batteries and related energy materials for a long time. He took the lead in putting forward the academic idea of using light element, multi electron and multi ion reaction system to realize the leap forward improvement of battery energy density, and developed a new system and key materials of high specific energy secondary batteries. Since the late 1980s, Academician Wu Feng has served as the first responsible expert of the National 863 high technology program, taking the lead in organizing and leading the research and development of key materials for lithium batteries, new hydrogen storage materials, nickel metal hydride batteries and lithium-ion batteries in China.
It is worth mentioning that Academician Wu Feng invented lithium containing hydrogen storage alloy and its preparation method, broke the foreign patent monopoly on hydrogen storage alloy, presided over the establishment of China’s first pilot test base of Ni MH battery, realized the integration of key technologies of industrialization, and designed and built China’s first automatic demonstration production line of Ni MH battery; A series of Ni MH power battery packs have been developed and successfully applied to a variety of hybrid vehicles.
