A successive ‘‘conversion-deposition” mechanism achieved by micro-crystalline Cu2O modified current collector for composite lithium anode

Yifei Cai,Bin Qin,Chun Li,Xiaoqing Si,Jian Cao,Xiaohang Zheng,LIANG QIAO,Junlei Qi 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-

Lithium (Li) metal is a promising material for high-energy–density batteries, but it is still plagued byobvious capacity degradation and low average Coulombic efficiency resulting from dendrite Li propagation. One main reason is the electro-mechanic coupled failure of plated Li on the current collector, whichcontributes to non-dense Li deposition on the anode. Transition metal oxides (TMOs) with a conversiontypemechanism have been used directly as the anode materials for lithium ion batteries, which demonstratedbetter electro-mechanical stability than metal Li. Herein, a successive ’’conversion-deposition’’mechanism is ingeniously developed to restrain the generation of dendritic Li. Specifically, a microcrystallineCu2O modified current collector was prepared, in which Li+ are sequentially inserted intoCu2O and deposited in the form of Li metal at successive low potential. A Li-Cu half-cell based on thehybrid mechanism sustains a high Coulombic efficiency of over 99.3 % in up to 800 cycles. This work ingeniouslyinhibits the generation of dendrite Li by incorporating conversion-type materials withdeposition-dissolution type metal Li, which contributes to a novel concept for the design of functionalcurrent collectors for composite Li anodes.

Li가 첨가된 YPO4:Eu3+ 형광체 분말의 형광특성

이성수 한국물리학회 2009 새물리 Vol.59 No.5

YPO4:Eu3+ phosphors were synthesized at different temperatures and Li-doped Y(0.95-x)Eu0.05PO4:Li(x) (x=0.00, 0.05, 0.10, 0.15, and 0.20) phosphors were prepared by solid state reaction method for different concentrations of Li ions. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) to analyze the crystallinity and morphology of the phosphors. The excitation and emission spectra were also measured to reveal the luminescent properties of these phosphors. The emitted radiation was dominated by an orange peak at 593 nm due to 5D0⟶7F1 transition of Eu3+ ions While the concentration of Li+ ions increasing from 0 to 0.10 mol, the crystallinity, grain size and the photoluminescence brightness of these phosphors were improved. The results were discussed by comparing with similar reports published elsewhere. 소결온도를 1000, 1100, 그리고 1200 oC로 변화시키는 동시에 Li의 첨가량을 변화시키며 Y0.95-xLixPO4:Eu3+0.05 분말 형광체를 고상 반응법(solid state reaction)을 이용하여 제조하였다. 소결온도의 변화와 Li의 첨가량에 따른 결정성, 표면형상 및 형광특성의 변화를 분석하였다. X-선 회절실험에 의하면 소결 온도와 Li의 첨가량이 증가할수록 분말의 결정성이 향상되었으며, Y0.95-xLixPO4:Eu3+0.05 분말이 (200) 방향의 주 결정면을 가지며, (101), (112), (301) 및 (312) 피크를 가지는 다 결정상으로 성장하였음을 확인할 수 있었다. 전자주사현미경을 이용한 입자의 미세구조 측정을 통하여 Li 첨가와 소결온도가 증가할수록 입자의 크기가 커지고 균일하게 됨을 확인하였다. Li 첨가와 소결온도의 증가에 따른 형광 강도의 증가는 분말 입자의 결정성 및 입자형태의 균일성의 향상에 기인하며, Li 첨가량이 0.10 mol까지 증가할수록 형광세기가 증가함을 알 수 있었다.

Li₂ZrO₃를 이용한 합성가스내의 CO₂ 제거

박주원,강동환,유경선,이재구,김재호,한춘,Park, Joo-Won,Kang, Dong-Hwan,Yoo, Kyung-Seun,Lee, Jae-Goo,Kim, Jae-Ho,Han, Choon 한국공업화학회 2006 공업화학 Vol.17 No.3

$Li_{2}ZrO_{3}$의 $CO_{2}$ 제거능을 평가하기 위하여 열중량분석기(thermogravimetric analyser, TGA)를 사용하여 실험하였고 $Li_{2}ZrO_{3}$를 이용한 $CO_{2}$ 제거반응시 $H_{2}$와 CO의 영향을 평가하기 위하여 충전층 반응기를 이용하여 실험하였다. $Li_{2}ZrO_{3}$의 $CO_{2}$ 제거반응 초기속도는 가스유량 증가에 따라 일정하게 증가하였고 가스유량 100 mL/min 이상에서 기체경막저항 소멸에 따라 일정하게 유지되었다. $Li_{2}ZrO_{3}$와 $CO_{2}$의 반응차수는 1차임을 확인했으며 최적온도 구간은 $500{\sim}600^{\circ}C$로 나타났으며, XRD와 SEM을 이용하여 $Li_{2}ZrO_{3}$의 구조를 살펴본 결과 결정구조의 $Li_{2}ZrO_{3}$와 다공성의 $Li_{2}CO_{3}$/$ZrO_{2}$로 구성되어 있음을 확인하였다. 또한 $CO_{2}$ 내의 $H_{2}$ 존재는 $CO_{2}$ 제거반응에 영향을 미치지 않지만 CO의 경우 $Li_{2}ZrO_{3}$상의 $Li_{2}CO_{3}$(L)에 흡착되는 $CO_{2}$의 수착을 억제하는 것으로 나타났다. Reaction of $CO_2$ with $Li_{2}ZrO_{3}$ has been investigated in a TGA and the effects of $H_{2}$ and CO on the removal of $CO_{2}$ using $Li_{2}ZrO_{3}$ were evaluated in a packed bed reactor. The initial rate of $CO_{2}$ removal reaction of $Li_{2}ZrO_{3}$ increased with the increase of gas flow rate up to 100 mL/min and then was maintained, which implied the disappearance of the gas film resistance. The reaction of $CO_{2}$ with $Li_{2}ZrO_{3}$ took place as the first order and the range of optimum temperature was found to be about $500{\sim}600^{\circ}C$. XRD and SEM analysis showed the formation of crystalline $Li_{2}ZrO_{3}$ and porous $Li_{2}ZrO_{3}$/$ZrO_{2}$. The presence of $H_{2}$ did not affect the adsorption of $CO_2$ with $Li_2ZrO_3$. On the other hand, CO inhibited the sorption of $CO_{2}$ into $Li_{2}CO_{3}$(L) on $Li_{2}ZrO_{3}$.

Li_0.5La_0.5TiO₃와 Si박막을 갖는 구리 집전체의 Li free 음극으로써의 전기화학적 특성

이재준,김수호,이종민,윤영수,Lee Jae-Jun,Kim Soo-Ho,Lee Jong-Min,Yoon Young-Soo 한국전기화학회 2006 한국전기화학회지 Vol.9 No.1

Electrochemical properties of Cu foil current collector with a $Li_{0.5}La_{0.5}TiO_3$ Cu a Si thin film deposited by r.f sputtering as an anode for Li free battery were evaluated. The Cu foil current collectors were lied in and out of plasma during sputtering process. The X-ray diffraction results indicated that the as-deposited Si and $Li_{0.5}La_{0.5}TiO_3$ thin films in and out of plasma did not show any crystalline difference. The $Li_{0.5}La_{0.5}TiO_3$ film in plasma and Si film out of plasma showed better cyclability since crystalline $Li_{0.5}La_{0.5}TiO_3$ has much higher ionic conductivity and crystalline Si film is much sensitive far volume change during charge-discharge process. These results suggested that the deposition of amorphous Si on Cu foil current collector is much better for fabrication of Li free battery and it can be useful for the unique battery with a cycling number constraint of below 10. Li free 음극으로써 구리 foil 집전체에 $Li_{0.5}La_{0.5}TiO_3$ 및 Si 박막을 r.f, 스퍼터링법을 이용하여 증착하고 양극 물질로는 $Li[Co_{0.1}Ni_{0.15}Li_{0.2}Mn_{0.55}]O_2$를 이용하여 전기화학적 특성을 평가하였다. 박막 증착시 플라즈마 내(in-plasma)와 밖(out of plasma)에 구리 foil을 각각 위치시켰다. X-ray 회절 분석의 경우 각각의 조건에서 $Li_{0.5}La_{0.5}TiO_3$ 및 Si 모두 결정 특성의 차이를 발견할 수 없었다. $Li_{0.5}La_{0.5}TiO_3$의 경우 플라즈마 내에서 증착된 경우 그리고 Si 경우는 플라즈마 밖에서 증착된 경우 각각 싸이클 특성이 우수한 것으로 나타났다. 이는 $Li_{0.5}La_{0.5}TiO_3$ 경우 결정성이 존재할 경우 이온전도 특성이 우수하며 Si 경우 플라즈마 내에서 성장된 박막이 더욱 치밀하여 충방전 중 부피변화에 더욱 민감하였기 때문으로 판단된다. 이상의 결과로부터 (1)전지 용량을 갖는 5게 의한 표면 개질의 경우 구조적으로 안정할 수 있는 비정질 상의 Si이 보다 더 바람직하며 (2) 이온전도 특성을 보이는 $Li_{0.5}La_{0.5}TiO_3$와 같은 소재를 이용하여 표면 개질을 할 경우 Li의 확산이 더욱 용이한 구조가 바람직할 것으로 판단된다.

唐에 의한 淄靑節度使 李師道 멸망과 그 후

池培善(Ji, Bae-Sun) 백산학회 2008 白山學報 Vol.- No.79

Li Zheng-ji, who was a Goguryo migrant, entered on the stage during the suppression of The Rebellion of An Lu-shan. Li set up his cousin Hou Hsi-i as the I-qing-chieh-tu-shih in Qing-chou. Hou was afraid of his Li’s leadership and tried to eliminate Li Zheng-ji. However, Hou was banished by soldiers, and consequently, Li became a I-qing-chieh-tu-shih. Li died during his fight in cooperation with other chieh-tu-shihs against T’ang. After that, the position of I-qing-chieh-tu-shih was bequeathed to Li Na, Li Zheng-ji’s son. Later, Li Shi-gu, Li Na’s son, inherited that position. After Li Shi-gu died, his half brother Li Shih-tao labored to confirm the position from T’ang. Meanwhile, T’ang tried to conquer Li Shih-tao, attacking his territory from three sides. The fact that the position of Hai-yun-lu-yun-chia-Silla-Pohai-liang-fan-shih was monopolized by Lee’s family is an important key to the interpretation of the history of Korea-China relationship. In other words, it is a clue to prove the active trade between T’ang and Shilla or T’ang and Balhae around Shan-tung Peninsula from the late eighth century to the early ninth century. After the collapse of Lee’s family’s control of Shan-tung Peninsula, pacification of that area was beyond T’ang’s power. Probably, considerable number of Shilla’s 30,000 soldiers who had been mobilized by Tang’s request for the suppression of Li could have remained in Shan-tung area. As a result, a full-scale settlement of Shilla people was established around Shan-tung Peninsula. Therefore, it can be assumed that the foundation of Jang Bogo’s marine network was set up with the appearance of Lee’s family.

LiFePO₄와 Li₄P₂O₇의 ⁷Li MAS NMR 특성 연구

한덕영,박남신,이상혁,이학만,김창삼,Han, Doug-Young,Park, Nam-Sin,Lee, Sang-Hyuk,Lee, Hak-Man,Kim, Chang-Sam 한국결정성장학회 2011 한국결정성장학회지 Vol.21 No.1

[ $^7Li$ ]Magic Angle Spinning(MAS) NMR Spectroscopy를 활용하여 $Li_4P_2O_7$와 $LiFePO_4$ 물질에서 $^7Li$ 핵의 NMR 특성 및 화합물 분자내의 국부적 구조 연구를 수행하였다. $Li_4P_2O_7$와 $LiFePO_4$ 물질 연구는 리튬이온전지에서 고체-전해질 경계상(SEI, solid-electrolyte interphase) 물질 연구를 위한 것이다. $Li_4P_2O_7$와 $LiFePO_4$ 분말은 고상합성법으로 제조하였다.$^7Li$MAS NMR 실험은 $27^{\circ}C$에서 $97^{\circ}C$의 영역에서 변온 실험을 수행하였으며 이는 주변 온도 변화 환경에서 $Li_4P_2O_7$ 물질 내의 Li 핵의 구조 변화를 관찰하기 위한 것이다. $^7Li$ MAS NMR 측정 결과 시료 온도가 $27^{\circ}C$에서 $97^{\circ}C$의 온도 분포 영역에서는 $Li_4P_2O_7$ 물질 내부의 Li 핵은 구조적으로 변화하지 않는 것이 확인되었다. 금번 실험을 통하여 $LiFePO_4$ 분말에 5.0 wt%이내로 포함되어있는 $Li_4P_2O_7$ 물질의 $^7Li$ MAS NMR 신호를 측정할 수 있는 측정 조건을 알았다. [ $^7Li$ ]Magic Angle Spinning (MAS) NMR spectroscopy has been used to study the lithium local environments in $Li_4P_2O_7$ and$LiFePO_4$ materials. The purpose of this study was to know the structure of the solid electrolyte interphase (SEI) in lithium ion cells composed of $LiFePO_4$ as cathode material. $Li_4P_2O_7$ and $LiFePO_4$ were prepared by a solid-state reaction. The $^7Li$ MAS NMR experiments were carried out at variable temperatures in order to observe the local structure changes at the temperatures in $Li_4P_2O_7$ system. The $^7Li$ MAS NMR spectra of in $Li_4P_2O_7$ indicate that the lithium local environments in $Li_4P_2O_7$ were not changed in the temperature range between $27^{\circ}C$ and $97^{\circ}C$ Through this work, we confirmed that the small amount of $Li_4P_2O_7$ less than 5.0 wt% in $LiFePO_4$ could be clearly measured by the $^7Li$ MAS NMR spectroscopy at high spinning rate over than 11 kHz.

Li₂O-LiCl 용융염을 이용한 ZrO₂의 전기화학적 환원과정에서 발생하는 Li₂O의 손실

박우신,허진목,최은영,김종국,Park, Wooshin,Hur, Jin-Mok,Choi, Eun-Young,Kim, Jong-Kook 한국방사성폐기물학회 2012 방사성폐기물학회지 Vol.10 No.4

$Li_2O$-LiCl 용융염을 이용한 전해환원기술은 사용후핵연료로부터 우라늄 금속을 회수하기 위해 연구되고 있다. 이 전해환원기술에서는 $Li_2O$가 촉매로 이용되기 때문에 그 농도를 유지하는 것은 매우 중요한 운전인자이다. $ZrO_2$는 피복관의 주성분이 Zr이기 때문에 사용후핵연료에 불가피하게 함유되며, 본 연구에서는 $Li_2O$를 촉매로 이용하는 전해환원공정에서 $ZrO_2$의 거동을 살펴보았다. $Li_2O$와 $ZrO_2$의 화학반응과 전해환원공정 중에서의 생성물을 분석한 결과, $Li_2ZrO_3$와 $Li_4ZrO_4$가 주요하게 관찰되었고, 이는 $Li_2O$의 손실을 가져오는 원인이 된다. 즉, $ZrO_2$는 $Li_2O$를 소모하는 역할을 하며, 반응생성물은 전기화학적으로 안정하기 때문에 $Li_2O$의 손실이 불가피하게 된다. A molten salt technology using $Li_2O$-LiCl has been extensively investigated to recover uranium metal from spent fuels in the field of nuclear energy. In the reduction process, it is an important point to maintain the concentration of $Li_2O$. $ZrO_2$ is inevitably contained in the spent fuels because Zr is one of the main components of fuel rod hulls. Therefore, the fate of $ZrO_2$ in $Li_2O$-LiCl molten salt has been investigated. It was found that $Li_2ZrO_3$ and $Li_4ZrO_4$ were formed chemically and electrochemically and they were not reduced to Zr. The recycling of $Li_2O$ is the key mechanism ruling the total reaction in the electrolytic reduction process. However, $ZrO_2$ will have a role as a $Li_2O$ sink.

Direct p-doping of Li-TFSI for efficient hole injection: Role of polaronic level in molecular doping

Kim, Kiwoong,Jeong, Junkyeong,Kim, Minju,Kang, Donghee,Cho, Sang Wan,Lee, Hyunbok,Yi, Yeonjin Elsevier 2019 APPLIED SURFACE SCIENCE - Vol.480 No.-

<P><B>Abstract</B></P> <P>Bis(trifluoromethane)sulfonimide lithium salt (Li-TFSI) has been popularly employed as an efficient p-dopant that increases the conductivity of a hole transport layer (HTL) in perovskite solar cells and dye-sensitized solar cells. However, the working mechanism of the Li-TFSI dopant is a long-standing question. The hygroscopicity of Li-TFSI makes it difficult to isolate the exact doping mechanism. In this study, we unveil the role of Li-TFSI in the p-doping to the <I>N</I>,<I>N</I>′-di(1-naphthyl)-<I>N</I>,<I>N</I>′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) HTL. A series of systematic in situ measurements using ultraviolet and inverse photoelectron spectroscopy reveal that electron transfer from NPB to Li-TFSI occurs due to the lower-lying negative polaronic level of Li-TFSI rather than the positive polaronic level of NPB. The hole injection barrier between NPB and indium tin oxide is significantly reduced with Li-TFSI doping, enhancing the device performance of hole-only devices and organic light-emitting diodes dramatically. With excessive dopants, however, the agglomerative property of Li-TFSI became dominant, decreasing the doping efficiency. These results provide robust guidelines for developing an efficient doping method for a molecular system with high conductivity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Electronic structure of Li-TFSI and NPB was investigated using in situ UPS and IPES. </LI> <LI> Electron transfer occurred from NPB to Li-TFSI through their polaronic levels. </LI> <LI> Hole injection barrier was reduced by 0.70 eV with Li-TFSI doping. </LI> <LI> Device performance of OLEDs was significantly enhanced with Li-TFSI doping. </LI> <LI> With excessive dopants, agglomeration of Li-TFSI decreased doping efficiency. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Li2O-LiCl 용융염을 이용한 ZrO2의 전기화학적 환원과정에서 발생하는 Li2O의 손실

박우신,허진목,최은영,김종국 한국방사성폐기물학회 2012 방사성폐기물학회지 Vol.10 No.4

A molten salt technology using Li2O-LiCl has been extensively investigated to recover uranium metal from spent fuels in the field of nuclear energy. In the reduction process, it is an important point to maintain the concentration of Li2O. ZrO2 is inevitably contained in the spent fuels because Zr is one of the main components of fuel rod hulls. Therefore, the fate of ZrO2 in Li2O-LiCl molten salt has been investigated. It was found that Li2ZrO3 and Li4ZrO4 were formed chemically and electrochemically and they were not reduced to Zr. The recycling of Li2O is the key mechanism ruling the total reaction in the electrolytic reduction process. However, ZrO2 will have a role as a Li2O sink. Li2O-LiCl 용융염을 이용한 전해환원기술은 사용후핵연료로부터 우라늄 금속을 회수하기 위해 연구되고 있다. 이 전해환원기술에서는 Li2O가 촉매로 이용되기 때문에 그 농도를 유지하는 것은 매우 중요한 운전인자이다. ZrO2는 피복관의 주성분이 Zr이기 때문에 사용후핵연료에 불가피하게 함유되며, 본 연구에서는 Li2O를 촉매로 이용하는 전해환원공정에서 ZrO2의 거동을 살펴보았다. Li2O와 ZrO2의 화학반응과 전해환원공정 중에서의 생성물을 분석한 결과, Li2ZrO3와 Li4ZrO4가 주요하게 관찰되었고, 이는 Li2O의 손실을 가져오는 원인이 된다. 즉, ZrO2는 Li2O를 소모하는 역할을 하며, 반응생성물은 전기화학적으로 안정하기 때문에 Li2O의 손실이 불가피하게 된다.

Rate capability for Na-doped Li_1.167Ni_0.18Mn_0.548Co_0.105O₂ cathode material and characterization of Li-ion diffusion using galvanostatic intermittent titration technique

Lim, Sung Nam,Seo, Jung Yoon,Jung, Dae Soo,Ahn, Wook,Song, Hoon Sub,Yeon, Sun-Hwa,Park, Seung Bin Elsevier 2015 JOURNAL OF ALLOYS AND COMPOUNDS Vol.623 No.-

<P><B>Abstract</B></P> <P>Spherical Li<SUB>1.167</SUB> <SUB>−</SUB> <I> <SUB>x</SUB> </I>Na<I> <SUB>x</SUB> </I>Ni<SUB>0.18</SUB>Mn<SUB>0.548</SUB>Co<SUB>0.105</SUB>O<SUB>2</SUB> (0⩽ <I>x</I> ⩽0.1) particles were prepared by spray pyrolysis, and subjected to electrochemical characterization for lithium battery applications. It was confirmed that Na doping enhances the charge/discharge rate capability. The structure of prepared samples was characterized by XRD: the <I>c</I>-axis lattice parameter increases with increase in the amount of Na ions (parameterized by <I>x</I>, above). The Na-doped sample with <I>x</I> =0.05 shows capacities of 208 and 184mAhg<SUP>−1</SUP> at high current densities of 1.0C and 2.0C, respectively. These values are enhanced, compared to values of 189 and 167mAhg<SUP>−1</SUP> for the bare sample. The ratio of the capacity at 1.0C to that at 0.1C is enhanced from 77% for the bare sample to 84% for the Na-doped sample with <I>x</I> =0.05. The Li diffusion coefficients obtained from the galvanostatic intermittent titration technique (GITT) are higher for Na-doped samples than for the bare sample. In particular, the Na-doped sample (<I>x</I> =0.05), in the potential range around 4V, has a higher <I>D</I> <SUB>Li+</SUB> value of 3.34×10<SUP>−9</SUP> cm<SUP>2</SUP> s<SUP>−1</SUP>, compared with 1.35×10<SUP>−9</SUP> cm<SUP>2</SUP> s<SUP>−1</SUP> for the bare sample. The Na-doped samples (0< <I>x</I> <0.075) show high capacity retention: the Na-doped sample (<I>x</I> =0.05) shows a capacity retention of 92% compared to 83% for the bare sample.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Spherical Na-doped Li-rich cathode material prepared by spray pyrolysis. </LI> <LI> Na-doped samples show better rate capability than that of bare sample. </LI> <LI> Na-doped sample has higher <I>D</I> <SUB>Li+</SUB> value at 4V compared with that of the bare sample. </LI> <LI> The cycle performance was enhanced from 83% to 92%. </LI> </UL> </P>