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Paramagnetic resonance: user interviews 】 【 battery research methods in the rising star
takeaway
Recently, the instrument information network especially interviewed bing-wen hu of east China normal university, Mr Hu, please how to introduce the mri power battery field of scientific research.
Bing-wen hu
From NMR to seek breakthrough in the application of battery
What is your current research directions?Why choose this direction?
Now our team is using nuclear magnetic resonance (NMR) and magnetic resonance (EPR) these two kinds of magnetic resonance (NMR) technology research in the field of batteries, including lithium ion battery and sodium ion battery two large categories.In France I read bo main nuclear magnetic resonance (NMR) methodology during the period of development, after returning the beginning did not change the direction of research, development and many methods such as SHANGHAI, SHA +, etc.But work gradually faced a problem: the master is very difficult to learn in a short time nuclear magnetic methodology and make scientific research achievements.After investigation, I found the domestic do "battery - nuclear magnetic resonance (NMR)" research is scarce, then slowly began to learn to do some research, from the electrolyte to the cathode to the anode.My tutor JP love chat, wide field of vision.He told me many times that the French five national nuclear magnetic resonance (NMR) research center of research direction are the emphasis of the original;China is so big, the national nuclear magnetic resonance (NMR) research center layout is a bit less, and most in catalytic and biological direction, to avoid these directions, do some other direction.JP greatly profession at the age of 40, he has been encouraged me greatly diverted, the pursuit of "original have focus on a new direction."In the field of battery contact after a period of time, I found that the nuclear magnetic resonance (NMR) technology is far from enough, still need to support the results of paramagnetic resonance technique.So group in 2016 to the brook to apply for a Demo machine, then bought brooke E580 cw/pulse electron paramagnetic resonance spectrometer, the advantage of paramagnetic resonance, we slowly mining using paramagnetic resonance technology is constantly learning to research system of battery, eventually formed the nuclear magnetic resonance (NMR), paramagnetic resonance and the direction of battery such an intersection.
When magnetic resonance (NMR) technology is applied to the field of battery?Compared with other analytical instruments, the characteristics of magnetic resonance (NMR) technology in where?
At present, the domestic the research in the field of magnetic resonance (NMR) technology is applied to the battery is not much, I have learned about 3-5 team.Internationally, nuclear magnetic resonance (NMR) into the battery research is probably around 2000, started to do the related research after I return home in 2010.Paramagnetic resonance technology application in the field of battery here and there, in a very long period of time, the application of paramagnetic resonance is really started around 2015, compared with the nuclear magnetic resonance (NMR) technology is relatively late, our research in this aspect of basic began with the international synchronization, which began in 2016 to enter the field.
Compared with other analytical instruments, nuclear magnetic resonance (NMR) with paramagnetic resonance in battery research has many original place.
Nuclear magnetic resonance (NMR) is a macroscopic science tool, the element can obtain more comprehensive information, and other such as TEM of local information of elements, the overall lack of understanding.Nuclear magnetic resonance (NMR) research, Li Na, O, degree of differentiation of these elements also is stronger than other analytical techniques.Such as the judge Li ion in NaLiMnO2 battery location, the method of using nuclear magnetic resonance (NMR) can most directly to obtain Li ion in sodium layer or in any other layer.Paramagnetic resonance to the distinction between the element valence ability is very strong.At the time of testing V system, synchronous radiation technique is currently the most used, can be very clearly observed V4 +, the change of the V5 +, but a little change is not easy to distinguish the V3 +.However, in the paramagnetic resonance spectrum can very clearly identify the V3 +, this is the "bad" paramagnetic resonance.
What do you think of mri application prospect in the field of battery energy?
It should be said that magnetic resonance (NMR) technology in the field of battery application prospect is very bright.The information provided by nuclear magnetic resonance (NMR) and magnetic resonance (NMR) technology complement each other, can present a complete battery material information.In fact, the battery has a unique behavior "local amorphous" namely, cationic battery materials have some place is disorder, this kind of disordered structure in most of the other technology and can't get very good explanation, and nuclear magnetic resonance (NMR) with paramagnetic resonance can explain this phenomenon well.In addition, the battery inside and outside the structure is very different, so no matter from the Angle of phase transformation, or the Angle of the disorder, magnetic resonance (NMR) technology has its irreplaceable role.Is worth mentioning, the use of magnetic resonance (NMR), not repelled by the idea of synchrotron radiation, TEM, such as technology, technology can be complementary between some of the information.
Develop characteristic of EPR or more
Your lab, there are a few magnetic resonance instrument purchase, what is the time which platform is the main instrument of your current research?
Nuclear magnetic in our lab are solid nuclear magnetic spectrometer, each one 300 MHz, 400 MHz, 600 MHz spectrometer two, probably purchased in 2010-2014;Paramagnetic resonance spectrometer is started in 2018 to purchase, the paramagnetic resonance is the main instrument of our laboratory.
You based on the tablecloth Luke E580 paramagnetic resonance spectrometer what research work, which bright eye results produced?
We have just published in the article on JPCL, is paramagnetic resonance in the original application of NaCrO2 system can observe other paramagnetic technology not easily observed Cr5 + ions.Use of charging and discharging equipment, lower than 3.7 v, the stability of the battery is very good;Higher than 3.7 v, soon there was no signal.In fact, after the higher than 3.7 v, Cr3, + +, - > Cr5 and Cr5 + will dissolve in the electrolyte, led to a sharp attenuation performance.And want to get this information, the most direct and effective tool is paramagnetic resonance.Combination of paramagnetic resonance imaging tool, can see Cr ion's location is in on the diaphragm in the electrolyte, the result directly shows the great potential of paramagnetic resonance imaging technology.
I again slightly revealed some of the forthcoming research achievements: in situ paramagnetic resonance is the study of Li ion on the copper deposition process effective analysis means, resolution is much higher than that of magnetic resonance imaging (MRI), it makes me very excited;In addition, by in situ EPR observed the change of the lithium battery empty O, found the oxide (such as Co3O4) the unique role of O2, which helps to understand empty oxides with lithium battery cycle performance reasons.
About the E580 paramagnetic resonance spectrometer, how's your feeling?Why did choose this instrument?
E580, in general, convenient operation, strong function, can satisfy the needs of the advanced scientific research, after-sales service is better.For scientific research, the instrument is configurability of the more important thing, brooke according to my requirements, also equipped with L - band, X - band and Q - band, and imaging systems.When it comes to choosing this instrument reason: on the one hand, we start from 2016 rented a brook E580 Demo machine to do related research work, to now also has five years.On the other hand I need Q band and imaging systems, I learned that there is no other brands of spectrometer.
Forge ahead, constantly breakthroughs of mri
You feel the current development of magnetic resonance (NMR) technology can meet the needs of battery research?From the perspective of scientific research, you look forward to the future of magnetic resonance imaging instrument to which direction to development?
Use a word called "procrustean method", it is limited, can only do research according to the function of the instrument.Basic can satisfy the battery current magnetic resonance (NMR) technology research, I am most looking forward to the development of fast imaging function, at the same time in the higher sensitivity and imaging speed can be faster.Now imaging speed is relatively slow, in the past, the battery charge and discharge is 24 hours, half an hour to collect a spectrogram is no problem, but now the battery charge and discharge time may only need one hour, requires that present results within a few minutes.So if you want to study the problem of high charge and discharge, there must be a faster imaging technology and spectroscopy technique.
About the future development of magnetic resonance instrument, in fact, I have been also in accordance with the relevant work of perfecting the instrument.Original hardware design must be a general, rather than a dedicated instrument in the field of battery.We do some local changes according to the existing framework, gradually to the independent design a more suitable for the battery research tools.These jobs are relatively progress may be slow, but I still insist on, the goal is for battery system to optimize the magnetic resonance equipment and related technology, maintain our unique advantage in this area.
At present the country are vigorously develop new energy, battery industry is also very hot, can share with us your future work plan?
In the future, hope that through nuclear magnetic resonance (NMR) combined with paramagnetic resonance technology, find the root causes of pain difficult battery field.The positive materials, such as cationic disorder we use now, through the study of paramagnetic resonance found internal manganese ions gathered is the core of the performance attenuation factor, after will understand why the performance attenuation, to do some modification work is handy.
Although nuclear magnetic resonance (NMR) technology application compared to mature, but our team is constantly digging more applications.Paramagnetic resonance application time is not long, a lot of technology has not yet been applied, in recent years, so, I prefer to take the time to research paramagnetic resonance technology, applied to the battery in the system again.In the global scope, paramagnetic resonance and the application of magnetic resonance imaging technology is very scarce, so it will be my future a priority.