"If the energy density to further improve, more than 500 watts / kg, then from now on to consider the solid-state lithium batteries, as well as lithium-air batteries, lithium-sulfur batteries and other new electrochemical system to explore research," Chinese Academy of Engineering Chen Liquan The future development of the battery said. Long-term development of the electric vehicle industry requires technical reserves, solid-state battery is expected to become China's next generation of automotive power battery important technical line.
To understand the status of solid-state battery development
Why is the future of technology will be solid-state battery?
Lithium-ion batteries dominate the mainstream of today's technology, but in the long term, solid-state batteries may be better able to meet people's high energy and high security of the real needs.
Working principle, the solid-state lithium battery and the traditional lithium battery is no different. The traditional liquid lithium battery is called "rocking chair battery", rocking chair at both ends of the battery positive and negative poles, the middle of the liquid electrolyte. Li-ion like an athlete, rocking chair at both ends back and forth, lithium-ion from cathode to cathode and then to the positive movement of the process, the battery charge and discharge process is complete. Solid-state batteries, however, have solid-state electrolytes with densities and structures that allow more charged ions to converge at one end and conduct more current, which in turn boosts battery capacity.
Solid-state batteries have many advantages, prospects for development worth the wait. Among them, the two most obvious advantages are higher energy density, more secure operation. The use of all-solid electrolyte, the lithium-ion battery can not use lithium-embedded graphite anode, but the direct use of lithium metal anode, which can greatly reduce the amount of anode material, making the energy density of the battery has improved significantly. Now in many laboratories, have been able to small-scale batch production of energy density of 300-400Wh / kg of all solid-state batteries. Solid-state batteries will not work at high current due to the emergence of lithium dendrites and pierce the diaphragm leading to short-circuit, will not occur at high temperatures side reactions, will not produce gas combustion, therefore, security is considered solid-state battery development One of the most fundamental driving force.
However, solid state batteries have drawbacks. Solid electrolyte overall conductivity is low, resulting in the overall low rate performance, internal resistance, charging speed is slow, and the overall cost is high, and now the solid-state batteries and ordinary lithium-ion batteries if the traditional market competition, and no Too much advantage. Therefore, to play a solid-state battery itself, high security, high temperature stability, flexibility and other features may be achieved, with the traditional lithium-ion battery in differentiated competition in the market, may be solid-state battery in the near future more promising market breakthrough direction.
Research and Development Status of Solid State
In materials, the Chinese Academy of Sciences, Ningbo Institute of Materials Technology and Engineering, Shanghai Institute of Silicate, Chinese Academy of Sciences as the representative team, has developed a series of oxides and sulfide powder, ceramic, etc., has begun to society Samples and supplies are available.
The Institute of Chemistry, Chinese Academy of Sciences, has successfully developed a novel bifunctional polymer electrolyte and has achieved high room temperature ionic conductivity and mechanical strength by using UV curing technology in the study of bifunctional polymer electrolyte. It can be used as solid lithium metal at room temperature battery. Qingdao Institute of Bioenergy and Processes of the Chinese Academy of Sciences in the high-energy-density solid-state battery research progress, solid-state battery development for solid-solid interface impedance is too large a bottleneck, the research team members creatively proposed "in situ self-formed solid electrolyte" solution , Effectively reduce the interface impedance and enhance the battery performance. At present, Qingdao Energy Institute of Chinese Academy of Sciences has developed a large capacity three-dimensional solid lithium battery 6Ah, with high energy density, long cycle life, good safety and other advantages. January 15, 2017, the research and development of the solid-state lithium battery with the Chinese Academy of Sciences Institute of deep-sea submersible, went to the Mariana Trench for deep sea demonstration application, which is China's first independent research and development can be applied to the deep dive High-energy-density, high-performance all-solid-state lithium battery.
In addition, by the South China Institute of Tsinghua University, academician of the team created Qingtao (Kunshan) Energy Development Co., Ltd. is also the earlier launch of all solid-state lithium battery technology research and development team. "The development of all-solid-state battery industry as the primary task of 2017, will focus on solving the material matching, equipment upgrades, product consistency and other core issues, and strive to September 2017 launch of the first A group of all solid-state lithium battery products.
Enterprise solid-state battery layout
Battery China Network found that Toyota, Panasonic, Samsung, Mitsubishi and domestic Ningde era battery industry leaders have been active in the layout of solid-state battery research and development reserves.
Relatively speaking, the technology is more mature, technology deep precipitation undoubtedly the French Bolloré, the United States Sakti3 and Toyota. The three are also representative of the polymer, oxide and sulfide three solid-state electrolyte development of typical technology direction. In Europe, the more famous Bolloré, using a polymer electrolyte system, Samsung is the use of sulfide electrolyte system. British tycoon James - Dyson (James Dyson) in 2015 the company acquired solid-state battery business Sakti3, August 2016, Dyson said it would invest 1.4 billion US dollars to build a battery factory. German auto parts giant Bosch (BOSCH), in 2015 the acquisition of the US battery company "Seeo". Bosch and Seeo and then with the famous Japanese GS YUASA (Yuasa) battery company and Mitsubishi Heavy Industries jointly established a new factory, the main solid-state anode lithium-ion battery.
On December 17, 2016, Ningde era R & D manager Guo Yongsheng in the "seventh global new energy vehicles General Assembly (GNEV7)" on the company's solid lithium metal battery R & D process, he said, Ningde era before doing solid- Do solid-state battery business to do research, the project is still in its early stages. Ningde era in the research and development process, but also concerned about the manufacturing of solid-state batteries, solid-state battery manufacturing process with the traditional lithium-ion manufacturing process is different from the need for new equipment, new technology, so Ningde times also process research and development.
Overall, the maturity of solid-state battery technology is still to be strengthened, to form the scale of production capacity of enterprises is limited, technology scale expansion need to overcome the difficulties are still in the promotion and development period. But it is expected that, with the continuous development of R & D and industrial technology, all-solid-state batteries in the scientific and technological issues will gradually be eased in the next few years, solid-state battery products will usher in the booming market opportunities.