Source: China Science Daily
Unmanned aerial vehicles, electric vehicles, electric aircraft and so on to achieve “long range”, has been a highly anticipated thing.However, in the absence of power systems with stable “storage” and “supply” capabilities, this expectation is always disappointed.The good news is that 3D printing could help solve the problem.
Sun Jingyu, a professor at soochow University’s School of Energy, and Liu Zhongfan, a professor at Peking University and academician of the Chinese Academy of Sciences, have recently built a 3D-printed sulfur anode, and obtained a lithium sulfur battery with high performance and surface capacity.Related technologies can also be extended to other emerging energy storage devices, providing important reference for the development of new, efficient and large-scale electrode construction methods.
The related research results were recently published in the international energy field high-level journal “Nano Energy” on the journal.
3D Printing technology “Supports”
Since its birth, 3D printing technology has been applied to medical treatment, military industry, aerospace, automobile, electronics and other fields.In addition, it has been preliminarily applied in energy storage systems such as lithium ion battery, lithium oxygen battery and zinc ion battery.Zhongfan Liu and Jingyu Sun’s team have been focusing on the research of enocarbon energy materials and applied technologies for a long time.In recent years, they have found new ideas and inspirations from 3D printing technology.
According to Sun, 3D printing technology has many advantages, such as facilitating the construction of self-supporting fluid-free electrodes with multistage pore structures and facilitating the rapid transmission of ions and electrons.The 3D printing technology can control the electrode material load by controlling the number of printing layers, which breaks the thickness limit of the electrode prepared by the conventional coating method, so as to obtain the battery system with high capacity per unit surface.In practical application, it can meet the requirements of customized and large-scale energy storage devices.
“However, there are still many key bottlenecks in 3D printing technology for energy storage applications, such as higher requirements on equipment configuration for electrode printing accuracy, urgent systematic exploration of printing ink preparation technology, and lack of large-scale printing equipment.”Sun Jingyu said.With the help of 3D printing technology, researchers conveniently, efficiently and conveniently constructed the sulfur anode with high load.The architecture has optimized ion/electron transport channels and sufficient porosity for efficient management of polysulfide.
In order to better suppress the shuttle effect mentioned above, the researchers also have a unique design for the printing ink.Sun Jingyu introduced that in recent years, the industry has a strong interest in the construction of metal borides high-performance lithium sulfur batteries.Among them, lanthanum hexaboride (LaB6) with similar properties has been widely used in many fields as a low-cost and sustainable compound.
Based on this, they designed a mixed ink containing sulfur/carbon and LaB6 electrocatalysts for printing high-performance sulfur positive electrodes.LaB6 electrocatalysts, a gold property, can be evenly distributed within the framework of 3D printing, spontaneously ensuring a wealth of active sites for the fixation and transformation of polysulfide, so as to achieve a high-efficiency discharge or charging process.
“This plays a positive role in the control of polysulfide and more effectively inhibits the ‘shuttle effect’, resulting in a lithium sulfur battery system with excellent performance.At the same time, it provides a new idea and strategy for designing the anode structure of lithium sulfur battery and improving the reaction kinetics of sulfur anode.Liu zhongfan said that this research is the first time to introduce efficient electrocatalysts into printable ink to construct 3D-printed positive sulfur electrodes, and obtain lithium sulfur batteries with high performance and surface capacity.
Barriers still stand in the way of practicality
In recent years, the continuous innovation of new technologies and methods and the accelerated transformation of scientific and technological achievements have promoted the practical development of high-performance lithium sulfur batteries.The lithium-sulfur battery pack jointly produced by Chen Jian’s team and Zhongke Pice Energy Storage Technology Co., Ltd. relying on scientific and technological achievements of dalian Institute of Chemistry and Physics, Chinese Academy of Sciences, has been successfully tested on large-wingspan and high-speed UAVs.
“This lithium-sulphur battery lasts 2.5 times longer than a lithium-ion battery of the same weight.”In the future, the number of battery cycles will need to be further improved, and to achieve this, the “shuttle effect” problem will need to be solved, Chen said.”In the process of application and industrialization, there are still many key problems to be solved in lithium sulfur electrode.The development of 3D-printed self-supporting sulfur positive poles is of concern.””Mr Liu said.
Sun added that in addition to the requirement for large-scale preparation of high-load sulfur electrodes, three aspects need to be considered.
The first is the positive carbon content.Sun pointed out that in order to solve the problem of sulfur insulation, it is usually necessary to add more conductive carbon to balance, resulting in low volume and energy density of lithium sulfur batteries.Therefore, in order to obtain lithium sulfur batteries with high volume energy density, it is necessary to improve the vibrational density of the positive sulfur electrode and to adopt the low carbon or even no carbon sulfur host.
The second is the amount of electrolyte.”Due to the porous nature of the positive sulfur electrode, a large amount of electrolyte is required. In order to achieve a lithium sulfur battery with high energy density, the pore structure of the positive electrode needs to be optimized to reduce the amount of electrolyte.”Sun Jingyu said.
In addition, the lithium anode is also one of the key problems, that is, in the large-scale lithium sulfur system, the dendrite growth must be suppressed to ensure the safety of lithium anode.
“In the future, as an extension of this research, we hope to develop truly low-carbon or even carbon-free, lean electrolyte and high-sulfur battery systems.”Sun Jingyu said.