去年MIT ME找了一個國內出來的在MTU高電化學畢業的FEMALE到助理教授。很PP，但是有人
在BBS MIT說，終於在MIT找到個混混教授，質疑她的學校(排名很差)，認為是因為是FEMA
LE得到的機會，認為MIT不過而而。我當時為她辯護，認為從學校看人很不對。而且她做的電池
領域是比較HOT的，比較好的大多去了工業界。有人總是說教授就是最好的，但是在工程領域，絕對是不一定的。我們系的一個老師快TENURE，但是認為太累，錢也不多，就去研究結構了。大學並沒有什麼特別高尚的地方。)我知道她工作很辛苦，很瘋狂，她的美國學生告訴我的。助理教授不管是誰為了TENURE都是很拼命的，而且從頭同時建立新的設施，很不容易，手下學生也不多。不想被網上的人攻擊為她很變態，真的是沒有辦法。好的是很短的時間就有很好的成果，
發了很好文章，還上了學校WEBSITE的首頁，恨大的榮譽。不知道以前的人有什麼感想。第一作者是她。我相信主要工作是她做的，因為他的美國學生主要在學習，而且什麼東西大多是她親自做的。
我想這兒有幾點：
1：不以學校看人。MIT不錯。自己畢業的博士或其它學校的博士都沒有問題。MIT有自己的
找人哲學。沒有強行限制本校博士，沒有看不起排名很差的學校。
2：發展新學科。她在的ME有12個方向，基本所有工程方向都在ME有涉及。ME為了發展電動
汽車建立一個很大研究隊伍。她來做電池也是其中的一環。其實應該是化學或化工或材料的東
西。ME不受這個限制，而是從學科的角度。當然她的學生基本就不是ME的了，我們MSE的。清華的能源國家實驗室可以考慮電池的。材料等學科介入，其實材料就是為別人服務的。也可以彌補沒有材料國家實驗室的遺憾。能源是很有文章可以做的。不要小看。
3：年輕教授要得到承認主要還是要靠自己的努力。用成績說話，沒有人可以否定的。
Yang Shao-Horn
Assistant Professor of Mechanical Engineering
Atlantic Richfield Career Development Professor
Education
1992, B.S., Beijing Polytechnic University; 1998, Ph.D., Michigan Technologica
l University
First lithium pictures could aid battery research JUNE 16, 2003
Contact
IMAGE COURTESY YANG SHAO-HORN, MICHAEL O'KEEFE, NATIONAL CENTER FOR ELECTRON M
ICROSCOPY
A computer simulation shows how columns of atoms in lithium cobalt oxide, seen
end-on, ought to appear. The inset is the actual image taken with a transmiss
ion electron microscope. It shows the arrangement of lithium ions among cobalt
and oxygen atoms in the compound lithium cobalt oxide. The oxygen atoms are b
right and sharp-edged, the cobalt atoms are fuzzy, and the lithium atoms are s
mall, weak, and look a little stretched.
PHOTO / DONNA COVENEY
Yang Shao-Horn is first author on a paper reportiing the first time scientists
have been able to "see" lithium atoms.
MORE INFORMATION
Yang Shao-Horn - MIT Dept. of Mechanical Engineering
>
CAMBRIDGE, Mass.—In work that could aid the development of better batte
ries for products from laptop computers to electric cars, an MIT engineer and
colleagues have taken the first images of individual atoms of lithium, a key i
ngredient in state-of-the-art rechargeable batteries. Only atoms of hydrogen a
nd helium are smaller and lighter than those of lithium.
"The atomic resolution of lithium atoms is a novel and significant achievement
, with implications for better understanding not only of lithium ion battery m
aterials but of many other electroceramic materials as well," said Yang Shao-H
orn, an assistant professor in MIT's Department of Mechanical Engineering and
lead author of a paper on the work to appear in the June 15 issue of Nature Ma
terials.
Her coauthors are Laurence Croguennec, Claude Delmas, E. Chris Nelson, and Mic
hael O'Keefe. Croguennec and Delmas are from the Institute de Chimie de la Mat
ière Condensée de Bordeaux-CNRS and the Ecole National Supèrieure de Chimie
et Physique de Bordeaux at the University of Bordeaux I. Nelson and O'Keefe a
re from Lawrence Berkeley National Laboratory.
The team used a transmission electron microscope—the One Angstrom Microscope
at the Department of Energy's National Center for Electron Microscopy at Berke
ley Lab—to simultaneously resolve columns of lithium, cobalt, and oxygen atom
s in the compound lithium cobalt oxide (LiCoO2).
LiCoO2 is commonly used in the positive electrodes of lithium rechargeable bat
teries, whose operation is based on reversible insertion and removal of lithiu
m ions to and from their positive and negative electrodes. Widely used in lapt
op computers, digital cameras, and many other devices, lithium ion batteries s
tore more energy for their weight, operate at a higher voltage, and hold a cha
rge much longer than other rechargeable batteries.
To improve their performance will require understanding how the atoms in the e
lectrode materials—and the vacancies left by moving ions—are arranged in 3-D
on the atomic scale. Although the structure of LiCoO2 is known theoretically
and has been confirmed with other techniques, lithium ions have never been see
n by these techniques, nor have they been seen in previous attempts to image L
iCoO2 with electron microscopy.
Thus when Shao-Horn approached microscopist O'Keefe in the summer of 2001 to a
sk whether it would be possible to image lithium ions in the material with a h
igh-resolution transmission electron microscope (TEM), his first answer was, "
I don't think so."
But using a computer simulation program developed by O'Keefe, the researchers
determined such essential information as what resolution the One Angstrom Micr
oscope had to achieve to see anything at all, and at what resolution all the d
ifferent kinds of atoms should be sharpest.
The program showed that in a sample of the right thickness, lithium ions shoul
d become visible at 1 angstrom (an angstrom, symbolized Å, is a ten-bill
ionth of a meter). And at 0.8 Å all three kinds of atoms should be clear
ly visible—a resolution that was, indeed, just possible to reach with the One
Angstrom Microscope.
O'Keefe says the computer program "showed that the columns of oxygen atoms sho
uld look bright and sharp-edged, the cobalts should be fuzzy, and the lithium
should be small, weak, and look a little stretched."
In 2002, working with Berkeley Lab's Nelson to master the operation of the One
Angstrom Microscope, Shao-Horn obtained many series of 20 differently focused
images of individual crystals from a LiCoO2 powder sample. The sample was pre
pared and well characterized by conventional X-ray diffraction in collaboratio
n with her colleagues at the University of Bordeaux I.
Using a second computer program and their measurements of the microscope param
eters, the researchers took the experimental images and worked backwards to pr
oduce a representation of the electron wave leaving the exit surface of the sp
ecimen. They then used the program to produce an image from a small area of a
thin edge of a LiCoO2 crystal.
Says O'Keefe, "We have shown that the range of the One Angstrom Microscope, an
d mid-voltage microscopes like it, can be extended all the way from heavy atom
s down through oxygen, nitrogen, and carbon to the lightest metal—in fact, ex
cept for helium and hydrogen, the lightest atoms of all."
