A New Concept on Resources Circulation Policy for Electric Vehicles in Korea (Republic of)

( Yong Choi ),( Hyeong-jin Choi ),( Sueng-whee Rhee ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 ISSE 초록집 Vol.2019 No.-

Globally, advanced countries will be prohibiting the sale of vehicles using internal combustion engine and promoting the supply of electric vehicles in order to reduce fine dust, air pollutants and carbon dioxide from vehicles. In Korea, 430,000 electric vehicles will be supplied by 2022 according to the atmospheric environmental policy. As the market for electric vehicles may be expanding at home and abroad, lithium ion secondary batteries from electric vehicles will be expected to be generated as wastes gradually. The lithium ion secondary batteries contain various valuable materials such as lithium, cobalt, manganese, nickel, iron, etc. According to Korea Mineral Resource Information Service (KOMIS), the price of lithium increased 2.1 times from 7,576 U$/ton in 2015 to 15,534 U$/ton in 2018. The price of cobalt increased 2.5 times from 28,613 U$/ton to 72,824 U$/ton during the same period. Therefore, it is industrially very economical that valuable materials are recovered from the lithium ion secondary battery. In advanced countries, various resources circulation policies are being used to recover and recycle lithium ion secondary batteries in electric vehicles. In the European Union and Japan, the lithium ion secondary batteries are managed by the Expanded Producer Responsibility (EPR) system and a recycling council was established to recycle the lithium ion secondary batteries continuously. Also, China announced regulations on the recycling of lithium ion secondary batteries for vehicles in 2015, strengthening resources circulation capacity for lithium ion secondary batteries. Electric vehicles are being promoted in Korea but the resources circulation policy for lithium ion secondary batteries is insufficient. In this study, the current status of resources circulation policy for lithium ion secondary batteries from electric vehicles in advanced countries is reviewed. In Korea, a new concept on the policy for the activation of resources circulation for lithium ion secondary battery should be introduced step by step including production, consumption, collection and recycling stage. The new concept of resources circulation policy can be applied in many fileds, including the securing of recycling technology, the construction of capacity build, and the establishment of management system such as EPR system.

리튬 이온 전지용 리튬 코발트 산화물 양극에서의 삽입 전압과 리튬 이온 전도

김대현,김대희,서화일,김영철,Kim, Dae-Hyun,Kim, Dae-Hee,Seo, Hwa-Il,Kim, Yeong-Cheol 한국전기화학회 2010 한국전기화학회지 Vol.13 No.4

본 연구는 밀도 범함수 이론을 이용하여 Li이온전지에 사용되는 Li코발트 산화물에서의 Li이온 삽입 전압과 전도에 관한 것이다. Li이온은 Li코발트 산화물 원자구조의 각 층을 1개씩 채우거나 한 층을 다 채우고 다음 층을 채울 수 있다. 평균 삽입 전압은 3.48V로 동일하나, 전자가 후자보다 더 유리하였다. 격자상수 c는 Li농도가 0.25보다 작을 때는 증가하였으나, 0.25보다 클 때는 감소하였다. Li농도가 증가하면, Li코발트 산화물에서의 Li이온 전도를 위한 에너지 장벽은 증가하였다. Li이온전지가 방전 중 출력 전압이 낮아지는 현상은 Li농도 증가에 따른 삽입 전압의 감소와 전도 에너지 장벽의 증가로 설명할 수 있었다. We performed a density functional theory study to investigate the intercalation voltage and lithium ion conduction in lithium cobalt oxide for lithium ion battery as a function of the lithium concentration. There were two methods for the intercalation of lithium ions; the intercalation of a lithium ion at a time in the individual layer and the intercalation of lithium ions in all the sites of one layer after all the sites of another layer. The average intercalation voltage was the same value, 3.48 V. However, we found the former method was more favorable than the latter method. The lattice parameter c was increased as the increase of the lithium concentration in the range of x < 0.25 while it was decreased as increase of the lithium concentration in the range of x > 0.25. The energy barrier for the conduction of lithium ion in lithium cobalt oxide was increased as the lithium concentration was increased. We demonstrated that the decrease of the intercalation voltage and increase of the energy barrier as the increase of the lithium concentration caused lower output voltage during the discharge of the lithium ion battery.

리튬 이온 배터리의 가스 발생 특성에 대한 연구

이준혁(Joon-Hyuk Lee),홍성호(Sung-Ho Hong),이흥수(Heung-Su Lee),박문우(Moon-Woo Park) 한국화재소방학회 2021 한국화재소방학회논문지 Vol.35 No.5

리튬이온배터리 화재 및 폭발의 주요 원인 중 하나는 배터리에서 발생하는 가연성 가스이며, ESS와 같이 배터리 다수가 밀집된 경우 열폭주 및 화재 전이로 인한 위험성이 크다. 이에 따라 국내·외에서 리튬이온배터리의 가스 발생 및열폭주 현상을 예측하고 예방하기 위한 연구가 다수 진행되고 있으나 아직 현재진행형인 실정이다. 따라서, 본 연구에서는 리튬이온배터리 열폭주 전후에 발생하는 가스를 분석하여 열폭주로 인한 위험을 경감시킬 수 있는 기반을 마련하고자 한다. 발생 되는 가스의 종류 및 특성 등을 파악하여 열폭주 시 조기 감지에 의한 예방의 토대를 구축하는 것이다. 실험을 위해 리튬이온배터리를 외관별(원통형, 각형, 파우치형), 양극재별(NCM, NCA, LFP)로 구분하였고 가로, 세로,높이가 각 1.5 m인 챔버 내에서 리튬이온배터리에 열적 이상 조건을 가하여 시간별로 발생하는 가스를 측정하였다. 가스 측정을 위해 FT-IR 분석장치를 사용하였으며, 별도의 수소 센서를 챔버 내에 설치하여 리튬이온전지의 시간별 가스종류 및 측정량 변화를 분석하였다. 실험 결과, 모든 리튬이온배터리에서 CO2와 CO가 가장 많이 발생 되었다. 열폭주이후 각형 및 파우치형에서는 CO2는 증가하고 CO가 감소하였으며, 원통형에서는 CO2와 CO 모두 증가하였다. 독성가스인 HF와 폭발범위가 넓은 H2 또한 발생되었으며, 두 가스의 농도는 상호 간 반비례 관계를 나타냈다. A main cause of fires and explosions in lithium-ion batteries is the generation of combustible gases by them, and whena large number of batteries are densely packed, like in an Energy Storage System, there is a high risk of thermal runawayand fire propagation. Currently, many studies are being conducted worldwide to predict and prevent the generation ofcombustible gases, and thermal runaway in lithium-ion batteries, but they are still in progress. Therefore, in this study, weanalyzed the gases generated before and after thermal runaway in lithium ion batteries, to prepare a basis for reducing therisk of thermal runaway. We aimed to establish the basis for prevention by early detection in the event of thermal runaway,by understanding the type and characteristics of the generated gases. For the experiment, lithium ion batteries were classifiedin terms of appearance (cylindrical, prismatic, pouch type), and cathode materials (NCM, NCA, LFP). The gases generatedwas measured against time. An FT-IR analyzer was used for gas measurement, and a separate hydrogen sensor was installedin the chamber to analyze changes in the types of gas, and measure the mass of the lithium ion battery over time. In theexperiment, CO2 and CO were generated the most during thermal runaway in all lithium-ion batteries. Thereafter, CO2increased, and CO decreased in the prismatic and pouch types, and both CO2 and CO increased in the cylindrical type. HF(a toxic gas), and H2 having a wide explosive range, were also generated, and the concentrations of these gases were inverselyproportional to each other.

Sn/SnO_x-loaded uniform-sized hollow carbon spheres on graphene nanosheets as an anode for lithium-ion batteries

Lee, Jeongyeon,Hwang, Taejin,Oh, Jiseop,Kim, Jong Min,Jeon, Youngmoo,Piao, Yuanzhe Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.736 No.-

<P><B>Abstract</B></P> <P>To meet the increasing demands for large-scalable application required high capacity and energy density, Sn-based materials as a promising anode for lithium-ion batteries have been widely studied. In this work, a carbon nanostructure of uniform-sized hollow carbon spheres on a graphene nanosheet was prepared by a facile synthesis process. The obtained nanostructure has numerous uniform-sized hollow carbon spheres with a diameter of ∼20 nm attached on graphene nanosheets, and mass production is considerably easy. Then, Sn/SnO<SUB>x</SUB> was loaded into the carbon nanostructure by a typical melt diffusion process, and its electrode delivers the high rate capability of 290.0 mA g<SUP>−1</SUP> at 3.0 A g<SUP>−1</SUP> and the good cyclability of 284.1 mA h g<SUP>−1</SUP> after 1000 cycles at 1.0 A g<SUP>−1</SUP>. The excellent electrochemical performance is attributed to the unique carbon nanostructure, which mitigates the volume expansion of Sn by the physical barrier of uniform-sized hollow carbon spheres and enables Li-ions or electrons to easily move by the improving electrical conductivity during discharge/charge process. Thus, the Sn loaded nanocomposite is expected to be a promising anode material for lithium-ion batteries.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A strategy is established for the synthesis of hollow carbon spheres on graphene nanosheets. </LI> <LI> The hollow carbon spheres were used as Sn/SnO<SUB>x</SUB> hosts for lithium ion battery. </LI> <LI> The carbon nanostructure could mitigate the volume expansion of Sn during the cycling. </LI> <LI> The electrode delivers an excellent reversible capacity even after 1000 cycles. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Sn/SnO<SUB>x</SUB>-loaded uniform-sized hollow carbon spheres on graphene nanosheets is fabricated from a facile solventless method and delivers good cycle ability for lithium-ion batteries.</P> <P>[DISPLAY OMISSION]</P>

72.5 Ah NCM계 파우치형 리튬이온배터리의 표면온도 상승률이 열폭주 발생시간에 미치는 영향 분석

이흥수,홍성호,이준혁,박문우,Lee, Heung-Su,Hong, Sung-Ho,Lee, Joon-Hyuk,Park, Moon Woo 한국안전학회 2021 한국안전학회지 Vol.36 No.5

With the convergence of the information and communication technologies, a new age of technological civilization has arrived. This is the age of intelligent revolution, known as the 4th industrial revolution. The 4th industrial revolution is based on technological innovations, such as robots, big data analysis, artificial intelligence, and unmanned transportation facilities. This revolution would interconnect all the people, things, and economy, and hence will lead to the expansion of the industry. A high-density, high-capacity energy technology is required to maintain this interconnection. As a next-generation energy source, lithium-ion batteries are in the spotlight today. However, lithium-ion batteries can cause thermal runaway and fire because of electrical, thermal, and mechanical abuse. In this study, thermal runaway was induced in 72.5 Ah NCM pouch-type lithium-ion batteries because of thermal abuse. The surface of the pouch-type lithium-ion batteries was heated by the hot plate heating method, and the effect of the rate of increase in the surface temperature on the thermal runaway trigger time was analyzed using Minitab 19, a statistical analysis program. The correlation analysis results confirmed that there existed a strong negative relationship between each variable, while the regression analysis demonstrated that the thermal runaway trigger time of lithium-ion batteries can be predicted from the rate of increase in their surface temperature.

2D layered Sb₂Se₃-based amorphous composite for high-performance Li- and Na-ion battery anodes

Nam, Ki-Hun,Park, Cheol-Min Elsevier 2019 Journal of Power Sources Vol.433 No.-

<P><B>Abstract</B></P> <P>A two-dimensional layered Sb<SUB>2</SUB>Se<SUB>3</SUB>-based amorphous composite (<I>a</I>–Sb<SUB>2</SUB>Se<SUB>3</SUB>/C) is synthesized using a simple solid-state ball-milling process, and its potential for Li- and Na-ion batteries is evaluated. <I>Ex situ</I> extended X-ray absorption fine structure analyses clearly indicate the electrochemical reaction mechanisms of Sb<SUB>2</SUB>Se<SUB>3</SUB> and <I>a</I>–Sb<SUB>2</SUB>Se<SUB>3</SUB>/C as anodes for Li- and Na-ion batteries. During Li- and Na-insertion, the Sb<SUB>2</SUB>Se<SUB>3</SUB> and <I>a</I>–Sb<SUB>2</SUB>Se<SUB>3</SUB>/C electrodes are converted into the final phases of Li<SUB>3</SUB>Sb/Na<SUB>3</SUB>Sb and Li<SUB>2</SUB>Se/Na<SUB>2</SUB>Se, respectively. During Li- and Na-extraction, the Li<SUB>3</SUB>Sb/Na<SUB>3</SUB>Sb and Li<SUB>2</SUB>Se/Na<SUB>2</SUB>Se in the Sb<SUB>2</SUB>Se<SUB>3</SUB> electrode are converted into Sb and Se, showing a non-recovery reaction, whereas a recovery to the original Sb<SUB>2</SUB>Se<SUB>3</SUB> in the <I>a</I>–Sb<SUB>2</SUB>Se<SUB>3</SUB>/C electrode occurs after full Li and Na extraction. Owing to the interesting conversion/recovery reaction, the <I>a</I>–Sb<SUB>2</SUB>Se<SUB>3</SUB>/C electrode exhibits excellent electrochemical performance, such as high reversible capacities (Li-ion battery: 662 mAh g<SUP>−1</SUP>; Na-ion battery: 407 mAh g<SUP>−1</SUP>), a long cycle life with highly reversible capacities (Li-ion battery: 662 mAh g<SUP>−1</SUP> and 1,205 mAh cm<SUP>−3</SUP>, respectively, after 100<SUP>th</SUP> cycle; Na-ion battery: 378 mAh g<SUP>−1</SUP> and 688 mAh cm<SUP>−3</SUP>, respectively, after 50<SUP>th</SUP> cycle), and high rate capabilities (Li-ion battery: 623 mAh g<SUP>−1</SUP> and 1,133 mAh cm<SUP>−3</SUP> at 3C; Na-ion battery: 270 mAh g<SUP>−1</SUP> and 492 mAh cm<SUP>−3</SUP> at 2C).</P> <P><B>Highlights</B></P> <P> <UL> <LI> A layered Sb<SUB>2</SUB>Se<SUB>3</SUB> and its amorphous Sb<SUB>2</SUB>Se<SUB>3</SUB>/C composite is synthesized simply. </LI> <LI> The reaction mechanisms during Li- and Na-insertion/extraction is demonstrated. </LI> <LI> The Sb<SUB>2</SUB>Se<SUB>3</SUB> had conversion/non-recovery reactions during Li- and Na-reactions. </LI> <LI> The Sb<SUB>2</SUB>Se<SUB>3</SUB>/C had conversion/full-recovery reactions during Li- and Na-reactions. </LI> <LI> The amorphous Sb<SUB>2</SUB>Se<SUB>3</SUB>/C exhibited excellent electrochemical performances. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Improved performance of iron oxide nanoparticles embedded in nitrongen doped carbon for lithium ion battery anodes

( Jinaihua ),유승호,성영은 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

Efficient energy storage devices with an extended lifetime are required to meet the increasing energy demands in various fields such as electronics, as well as for renewable energy generation systems and electric vehicles. Lithium ion batteries (LIBs) have attracted great attention as one of the most dominant power sources because of their high power and energy densities. In commercial industry, graphite was used as lithium ion batteries anode. However, graphite already approaches very close to the limited theoretical capacity (372 mA h g^-1) and graphite cannot satisfy the demand of high capacity storage. Therefore, many studies are focused on improving the specific capacity of LIB anode materials. Transition-metal oxides have been studied for use as anode materials due to their high specific capacity. Fe₃O₄ is one of them and the theoretical capacity is 924 mA h g^-1. Nitrogen doping of carbonaceous materials has been studied as an effective way to improve the electrochemical performance. In particular, nitrogen doping of carbon-based materials allows for enhanced interaction with lithium ions and the creation of a great number of active sites. Fe₃O₄ was synthesized by particularly simple way and exhibited improved electrochemical performance when they were employed as anode materials for lithium ion batteries. Fe₃O₄ nanoparticles embedded in nitrogen doped carbon show the reversible capacity as high as 700 mA h g^-1 over 100 cycles at current density of 200 mA h g^-1 in lithium ion batteries applications.

Investigating continuous co-intercalation of solvated lithium ions and graphite exfoliation in propylene carbonate-based electrolyte solutions

Song, Hee-Youb,Jeong, Soon-Ki Elsevier 2018 Journal of Power Sources Vol.373 No.-

<P><B>Abstract</B></P> <P>Forming an effective solid electrolyte interphase (SEI) is a significant issue in lithium ion batteries that utilize graphite as a negative electrode material, because the SEI determines the reversibility of the intercalation and de-intercalation of lithium ions into graphite for secondary batteries. In propylene carbonate (PC)-based electrolyte solutions, ceaseless co-intercalation of solvated lithium ions takes place because no effective SEI is formed. It is indisputable that this continuous co-intercalation leads to graphite exfoliation; however, the reason for this is currently not well understood. In this study, we investigate interfacial reactions that contribute to SEI formation on highly oriented pyrolytic graphite (HOPG) in ethylene carbonate (EC) and PC-based electrolyte solutions by in situ atomic force microscopy. The blisters formed on HOPG after the decomposition of solvated lithium ions within the graphite layers do not change over the course of ten electrochemical cycles in an EC-based electrolyte solution. In contrast, when cycling in PC-based electrolytes, the blisters continually change, and the height at the vicinity of the graphite edge plane increases. These morphological changes are attributed to the continuous co-intercalation of solvated lithium ions in PC-based electrolyte solutions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Graphite exfoliation is a problem in propylene carbonate (PC)-based electrolytes. </LI> <LI> Interfacial reactions affecting SEI formation were studied by in-situ AFM and CV. </LI> <LI> No changes were observed over 10 cycles in ethylene carbonate-based electrolytes. </LI> <LI> Overlapping blisters caused graphite exfoliation in PC-based electrolytes. </LI> <LI> PC-solvated Li ions can pass through the blister structures freely. </LI> </UL> </P>

패턴전사 프린팅을 활용한 리튬이온 배터리 양극 기초소재 Li₂CO₃의 나노스케일 패턴화 방법

강영림,박태완,박은수,이정훈,왕제필,박운익,Kang, Young Lim,Park, Tae Wan,Park, Eun-Soo,Lee, Junghoon,Wang, Jei-Pil,Park, Woon Ik 한국마이크로전자및패키징학회 2020 마이크로전자 및 패키징학회지 Vol.27 No.4

지난 수십년간 인류에게 핵심적인 에너지 자원이었던 화석연료가 갈수록 고갈되고 있고, 산업발전에 따른 오염이 심해지고 있는 환경을 보호하기 위한 노력의 일환으로, 친환경 이차전지, 수소발생 에너지 장치, 에너지 저장 시스템 등과 관련한 새로운 에너지 기술들이 개발되고 있다. 그 중에서도 리튬이온 배터리 (Lithium ion battery, LIB)는 높은 에너지 밀도와 긴 수명으로 인해, 대용량 배터리로 응용하기에 적합하고 산업적 응용이 가능한 차세대 에너지 장치로 여겨진다. 하지만, 친환경 전기 자동차, 드론 등 증가하는 배터리 시장을 고려할 때, 수명이 다한 이유로 어느 순간부터 많은 양의 배터리 폐기물이 쏟아져 나올 것으로 예상된다. 이를 대비하기 위해, 폐전지에서 리튬 및 각종 유가금속을 회수하는 공정개발이 요구되는 동시에, 이를 재활용할 수 있는 방안이 사회적으로 요구된다. 본 연구에서는, 폐전지의 재활용 전략소재 중 하나인, 리튬이온 배터리의 대표적 양극 소재 Li2CO3의 나노스케일 패턴 제조 방법을 소개하고자 한다. 우선, Li2CO3 분말을 진공 내 가압하여 성형하고, 고온 소결을 통하여 매우 순수한 Li2CO3 박막 증착용 3인치 스퍼터 타겟을 성공적으로 제작하였다. 해당 타겟을 스퍼터 장비에 장착하여, 나노 패턴전사 프린팅 공정을 이용하여 250 nm 선 폭을 갖는, 매우 잘 정렬된 Li2CO3 라인 패턴을 SiO2/Si 기판 위에 성공적으로 형성할 수 있었다. 뿐만 아니라, 패턴전사 프린팅 공정을 기반으로, 금속, 유리, 유연 고분자 기판, 그리고 굴곡진 고글의 표면에까지 Li2CO3 라인 패턴을 성공적으로 형성하였다. 해당 결과물은 향후, 배터리 소자에 사용되는 다양한 기능성 소재의 박막화에 응용될 것으로 기대되고, 특히 다양한 기판 위에서의 리튬이온 배터리 소자의 성능 향상에 도움이 될 것으로 기대된다. For the past few decades, as part of efforts to protect the environment where fossil fuels, which have been a key energy resource for mankind, are becoming increasingly depleted and pollution due to industrial development, ecofriendly secondary batteries, hydrogen generating energy devices, energy storage systems, and many other new energy technologies are being developed. Among them, the lithium-ion battery (LIB) is considered to be a next-generation energy device suitable for application as a large-capacity battery and capable of industrial application due to its high energy density and long lifespan. However, considering the growing battery market such as eco-friendly electric vehicles and drones, it is expected that a large amount of battery waste will spill out from some point due to the end of life. In order to prepare for this situation, development of a process for recovering lithium and various valuable metals from waste batteries is required, and at the same time, a plan to recycle them is socially required. In this study, we introduce a nanoscale pattern transfer printing (NTP) process of Li2CO3, a representative anode material for lithium ion batteries, one of the strategic materials for recycling waste batteries. First, Li2CO3 powder was formed by pressing in a vacuum, and a 3-inch sputter target for very pure Li2CO3 thin film deposition was successfully produced through high-temperature sintering. The target was mounted on a sputtering device, and a well-ordered Li2CO3 line pattern with a width of 250 nm was successfully obtained on the Si substrate using the NTP process. In addition, based on the nTP method, the periodic Li2CO3 line patterns were formed on the surfaces of metal, glass, flexible polymer substrates, and even curved goggles. These results are expected to be applied to the thin films of various functional materials used in battery devices in the future, and is also expected to be particularly helpful in improving the performance of lithium-ion battery devices on various substrates.

Unveiling origin of additional capacity of SnO₂ anode in lithium-ion batteries by realistic <i>ex situ</i> TEM analysis

Lee, Seung-Yong,Park, Kyu-Young,Kim, Won-Sik,Yoon, Sangmoon,Hong, Seong-Hyeon,Kang, Kisuk,Kim, Miyoung Elsevier 2016 Nano energy Vol.19 No.-

<P><B>Abstract</B></P> <P>The SnO<SUB>2</SUB> material has been considered as a promising lithium-ion battery anode candidate, and recently, the importance has been increased due to its high performance in sodium-ion batteries. Remarkably, the SnO<SUB>2</SUB> lithium-ion battery anode usually shows extra specific capacity that greatly exceeds the theoretical value. Partial reversibility of conversion reaction has been commonly considered to contribute the extra capacity, however, this has not clearly solved due to the indirect experimental evidences. Here, a realistic <I>ex situ</I> transmission electron microscopy (TEM) analysis technique was developed to reveal the origin of the extra capacity. We demonstrate that reactions of Li<SUB>2</SUB>O phase contribute to the extra capacity and the reverse conversion reaction of SnO<SUB>2</SUB> hardly occurs in the real battery system. This work provides significant implications for establishing an accurate electrochemical reaction mechanism of SnO<SUB>2</SUB> lithium-ion battery anode, which may lead to inspiration on enhancing performance of the SnO<SUB>2</SUB> anode in lithium- and sodium-ion batteries as well. Furthermore, the robust <I>ex situ</I> TEM experimental approach we have introduced is extensively applicable to analyses of various battery electrode materials.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Realistic <I>ex situ</I> TEM experimental technique for analysis of batteries was developed. </LI> <LI> Decreasing reactions of lithium oxide are mainly related with the extra capacity. </LI> <LI> Reverse conversion reaction of SnO<SUB>2</SUB> is scarcely possible. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Origin of extra capacities and partial reversibility of conversion reaction in SnO<SUB>2</SUB>/Li battery was investigated by transmission electron microscopy (TEM) studies. We applied the specialized <I>ex situ</I> TEM analysis technique to solve the controversial phenomena in the actual battery-operating environment. The experimental results show that lithium oxide phases are mainly related with the extra capacities and the conversion reaction does not seem to be reversible.</P> <P>[DISPLAY OMISSION]</P>