Recent progress in Co ‐free, Ni ‐rich cathode materials for lithium‐ion batteries

Hussain Sk. Khaja,방진호 대한화학회 2024 Bulletin of the Korean Chemical Society Vol.45 No.1

Cobalt (Co) has played an important role in nickel (Ni)‐rich cathode materials in terms of improving electrochemical performance, boosting energy density, and improving cycling life for lithium‐ion batteries (LIBs). While Co resources are becoming more cost‐effective, they pose environmental challenges that can lead to limitations in production and indicate the need for alternative Co‐free, Ni‐rich cathodes. This review aims to compile some of the concepts established in recent years to overcome the electrochemical disadvantages of Ni‐rich cathodes without Co. With the development of strategies involving single‐crystals, core‐shell structures, and substitution of Co by other metal ions, problems associated with capacity reduction and the underlying structure degradation mechanism have been resolved. Therefore, structural transformation strategies focusing on potential cathodes with improved energy density and lifetime have been pursued for safe LIBs. We also address possible issues and some new insights to improve the performance of Co‐free, Ni‐rich cathodes for practical applications. Cobalt (Co) has played an important role in nickel (Ni)-rich cathode materials in terms of improving electrochemical performance, boosting energy density, and improving cycling life for lithium-ion batteries (LIBs). While Co resources are becoming more cost-effective, they pose environmental challenges that can lead to limitations in production and indicate the need for alternative Co-free, Ni-rich cathodes. This review aims to compile some of the concepts established in recent years to overcome the electrochemical disadvantages of Ni-rich cathodes without Co. With the development of strategies involving single-crystals, core-shell structures, and substitution of Co by other metal ions, problems associated with capacity reduction and the underlying structure degradation mechanism have been resolved. Therefore, structural transformation strategies focusing on potential cathodes with improved energy density and lifetime have been pursued for safe LIBs. We also address possible issues and some new insights to improve the performance of Co-free, Ni-rich cathodes for practical applications.

The geochemical evolution of very dilute CO₂-rich water in Chungcheong Province, Korea: processes and pathways

KIM, K.,JEONG, D. H.,KIM, Y.,KOH, Y.-K.,KIM, S.-H.,PARK, E. Blackwell Publishing Ltd 2008 Geofluids Vol.8 No.1

<P>Abstract</P><P>A geochemical study was carried out on the CO<SUB>2</SUB>-rich water occurring in granite areas of Chungcheong Province, Korea. In this area, very dilute and acidic CO<SUB>2</SUB>-rich waters [62–242 mg l<SUP>−1</SUP> in total dissolved solid (TDS), 4.0–5.3 in pH; group I) occur together with normal CO<SUB>2</SUB>-rich waters (317–988 mg l<SUP>−1</SUP> in TDS, 5.5–6.0 in pH; group II). The concentration levels and ages of group I water are similar to those of recently recharged and low-mineralized groundwater (group III). Calculation of reaction pathways suggests that group I waters are produced by direct influx of CO<SUB>2</SUB> gas into group III type waters. When the groundwater is injected with CO<SUB>2</SUB>, it develops the capacity to accept dissolved solids and it can evolve into water with very high solute concentrations. Whether the water is open or closed to the CO<SUB>2</SUB> gases becomes less important in controlling the reaction pathway of the CO<SUB>2</SUB>-rich groundwater when the initial <I>p</I><SMALL>CO</SMALL><SUB>2</SUB> is high. Our data show that most of the solutes are dissolved in the CO<SUB>2</SUB>-rich groundwater at pH > 5 where the weathering rates of silicates are very slow or independent of pH. Thus, groundwater age is likely more important in developing high solute concentrations in the CO<SUB>2</SUB>-rich groundwaters than accelerated weathering kinetics because of acidic pH caused by high <I>p</I><SMALL>CO</SMALL><SUB>2</SUB>.</P>

강원지역에서 산출되는 탄산천의 수리화학 및 생성환경

정찬호 한국광물학회 2004 광물과 암석 (J.Miner.Soc.Korea) Vol.17 No.1

강원지역에서 산출되는 탄산천의 수리화학적 특성과 모암과의 관계, 그리고 생성기원에 대해서 해석하고자 하였다. 이 연구에서는 기존의 연구결과에 대한 재해석도 포함되어 있다. 강원지역의 13개 지역에서 탄산수 시료를 채취하였다. 탄산수의 수리화학적 특성을 보면 Pco₂는 0.787∼4.78 atm 범위의 높은 값을 보이고, 약산성 pH, 높은 전기전도도값(422∼2,280 ㎲/㎝)의 특성을 보인다. 탄산수의 화학적 유형은 Ca-HCO₃형, Na-HCO₃형, Ca(Na)-HCO₃형으로 구분된다. 아울러 강원지역 탄산수의 다량의 철과 불소를 함유하는 것이 특징이다. 탄산수의 화학적 성분과 모암의 화학분석 자료를 종합하면 Na-HCO₃형의 탄산수는 설악산일대 흑운모-칼리장석 화강암의 영향을 Ca-HCO₃형의 탄산수는 편마암과 화강남내 방해석등에 영향을 받는 것으로 보인다. 암석내 Na, K, Ca, Mg 함량과 탄산수내 그들의 함량과의 관계가 비례함이 이를 뒷받침한다. 불소는 Na-HCO₃형의 탄산수에서 높은 값을 보이고 철 성분은 Ca-HCO₃형의 탄산수에서 더 높은 함량을 보인다. 불소는 흑운모(흑은 복운모)화강암내 운모의 OH를 치환한 F성분의 용해에 의한 것으로 해석된다. 동위원소와 암석 성분 자료를 근거로 볼 때 모암의 광물화학성분이 탄산수의 화학적 유형을 결정한 것으로 보인다. 이를 확실히 뒷받침하기 위해서는 암종별 현미경적 관찰과 광물에 대한 화학성분 분석이 추가적으로 이루어져야 할 것이다. 탄산수의 δD과 δ^(18)O 값은 순환수선에 도시되며, δ^(13)C 값이 -0.3∼-6.2‰ PDB 범위를 보여 국내 다른 지역 탄산수와 거의 유사한 범위를 보인다. 탄산수는 지하 심부의 CO₂가스가 지표부로 상승하면서 순환하는 지하수와 혼합된 후 반응하는 모암에 따라서 다양한 화학적 유형의 탄산수가 생성된 것으로 해석된다. The purposes of this study are to investigate the occurrence, the hydrochemical characteristics and the origin of the CO₂-rich springs from the Kangwon Province, and to reanalyze the previous studied results of other researchers. The CO₂-rich water samples were collected at 13 locations in the Kangwon Province. The CO₂-rich water shows a high CO₂ concentration (P_(CO₂) 0.787 to 4.78 atm), weak acidic pHs, electrical conductivity values ranging from 422 to 2,280 μS/㎝, and high Fe and F contents. The chemical compositions of CO₂-rich water from this study area are classified into three types; Ca-HCO₃, Ca(Na)-HCO₃, Na-HCO₃ types. The chemical data of CO₂-rich waters and their host rocks indicate that Na-HC03 type water are mainly influenced by biotite, K-feldspar granite, and Ca(Na)-HCO₃, type water is chiefly influenced by gneiss and carbonate minerals in granite. F and Fe contents of Coprich waters are. abundant in Na-HCO₃, and Ca-HCO₃ types, respectively. The results of this study suggest that the chemical composition CO₂-rich water is mainly controlled by the mineralogical composition of aquifer host rocks. Oxygen and deuterium isotope data indicate that CO₂-rich water is meteoric origin. The δ^(13)C values (-0.3% to -6.2% PDB) suggest that dissolved carbonates are mainly derived from a deep-seated CO₂ and partly from carbonate minerals.

경북지역 탄산수의 생성기원과 수리화학적 특성

정찬호 대한자원환경지질학회 2002 자원환경지질 Vol.35 No.2

경북에서는 16개 지역에서 탄산수가 산출된다. 탄산수의 산출은 중생대 화강암과 경상누층군의 퇴적암류(또는 선캠브리아기 변성암)의 지질경계부 또는 단층대를 따라서 집중된다. 경북지역 탄산수는 매우 높은 CO₂의 함량(PCO₂=0.46-5.21 atm)과 422-2,280 μS/cm 범위의 전기전도도, Ca-HCO₃형의 수리화학적 특성을 보인다. 아울러 대부분의 탄산수는 다량의 Fe를 함유하는 것이 특징이다. 탄산수에 대한 δD과 δ18O 분석 값은 탄산수가 순환수 기원임을 지시한다. 탄산수의 높은 CO₂압력과 탄산염 침전물에 대한 δ13C 값이 -1.5- -6.1‰PDB 범위를 보여 탄산성분은 지하 심부에서 상승한 CO₂가스와 탄산염광물의 용해반응에 기원한 것으로 해석된다. 탄산수와 광물사이에 열역학적 평형관계와 탄산수의 수리화학적 특성을 보면 탄산수의 화학성분을 결정한 주요 근원광물은 사장석, 정장석, 탄산염광물 및 철산화물임을 지시한다. pH가 약산성이고, 높은 CO₂압력하에서 일부 탄산수를 제외한 대부분의 탄산수는 탄산염광물 및 앨바이트에 대해서 열역학적으로 용해성 환경에 있다. The CO₂-rich springs in the Kyungpook Proyince has been found at 16 locations. Most of the CO₂-rich springs outflow along either fault zones or the geologic boundary between Mesozoic granites and their adjacent rocks. The CO₂-rich water samples show a high CO₂concenoation (PCO₂ 0.46 to 5.21 atm), weak acidic pHs, wide electrical conductiyity values ranging from 422 to 2,280 μS/cm, and high Fe content. They are classified into the Ca-HCO₃type in chemical composition. δ18O and δ2H data indicate that CO₂-rich water is meteoric origin. The δ13C values(-1.5‰to -6.1‰PDB) suggest that dissolved H₂CO₃O and HCO₃- are mainly derived from a deep-seated CO₂and carbonate minerals. The thermodynamic equilibrium state between CO₂-rich water and major minerals, and hydro-chemical characteristics indicate that major source minerals determining the chemical composition of CO₂-rich water are carbonate minerals, plagioclase, K-feldspar and Fe-oxides. Under high CO₂pressure and the weak acidic condition, most of the CO₂-rich water samples are thermodynamically in the dissolution state with respect to albite and carbonate minerals.

Microbial diversity of two natural CO2-rich springs with contrasting hydrochemical features

고대근,도현권,김철환,윤성택,정혜근 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.6

Microbial communities in CO2-rich springs have adapted to environmental pressure including low pH resulting from high concentrations of CO2. Microbial community composition and hydrochemical characteristics in the CO2-rich springs are important features affected by high levels of CO2 in groundwater ecosystems, and they may be useful indicators of CO2 leakage from carbon capture and storage (CCS) sites where CO2 is injected into deep geological reservoirs for the mitigation of climate change. To determine how long-term CO2 leakage affects the groundwater ecosystems, we analyzed the bacterial and archaeal community composition and hydrochemical features of two different natural CO2-rich springs, Hansil (HS) and Chosukol (CS), located in south-eastern Korea which are natural analog sites for groundwater ecosystems affected by CO2 leakage from geological CO2 storage sites. Analyses of hydrochemical characteristics and 16S rRNA gene amplicon sequencing of bacteria and archaea revealed a marked distinction between the two springs. The pH, the concentrations of bicarbonate ion (HCO3–), major cations including Ca2+ and Mg2+, and specific trace elements including Fe and Mn were higher in HS as compared to CS while no distinction in pCO2 between the two springs was observed. Microbial community composition was distinct between the two springs at the genus level. Specifically, the relative abundance of Gallionella, an iron-oxidizer, was significantly higher in HS whereas that of Albidiferax known as dissimilatory iron-reducing bacteria was higher in CS than HS, reflecting the difference of iron concentration in the two springs. In our study, microbial community composition appeared to be more strongly affected by the concentration of iron than that of CO2. Our results enhance the understanding of hydrochemical features and microbial communities in natural CO2-rich springs and suggest that microbial communities may be useful indicators of CO2 leakage from CCS sites.

pH가 낮은 탄산수의 CO₂ 탈기에 따른 용존탄소동위원소 변화

채기탁,유순영,김찬영,박진영,방하은,이인혜,고동찬,신영재,오진만,Chae, Gitak,Yu, Soonyoung,Kim, Chan Yeong,Park, Jinyoung,Bang, Haeun,Lee, Inhye,Koh, Dong-Chan,Shinn, Young Jae,Oh, Jinman 한국지하수토양환경학회 2019 지하수토양환경 Vol.24 No.3

It is known that ${\delta}^{13}C_{DIC}$ (carbon-13 isotope of dissolved inorganic carbonate (DIC) ions) of water increases when dissolved $CO_2$ degases. However, ${\delta}^{13}C_{DIC}$ could decrease when the pH of water is lower than 5.5 at the early stage of degassing. Laboratory experiments were performed to observe the changes of ${\delta}^{13}C_{DIC}$ as $CO_2$ degassed from three different artificial $CO_2$-rich waters (ACWs) in which the initial pH was 4.9, 5.4, and 6.4, respectively. The pH, alkalinity and ${\delta}^{13}C_{DIC}$ were measured until 240 hours after degassing began and those data were compared with kinetic isotope fractionation calculations. Furthermore, same experiment was conducted with the natural $CO_2$-rich water (pH 4.9) from Daepyeong, Sejong City. As a result of experiments, we could observe the decrease of DIC and increase of pH as the degassing progressed. ACW with an initial pH of 6.4, ${\delta}^{13}C_{DIC}$ kept increasing but, in cases where the initial pH was lower than 5.5, ${\delta}^{13}C_{DIC}$ decreased until 6 hours. After 6 hours ${\delta}^{13}C_{DIC}$ increased within all cases because the $CO_2$ degassing caused pH increase and subsequently the ratio of $HCO_3{^-}$ in solution. In the early stage of $CO_2$ degassing, the laboratory measurements were well matched with the calculations, but after about 48 hours, the experiment results were deviated from the calculations, probably due to the equilibrium interaction with the atmosphere and precipitation of carbonates. The result of this study may be not applicable to all natural environments because the pressure and $CO_2$ concentration in headspace of reaction vessels was not maintained constant as well as the temperature. Nevertheless, this study provides fundamental knowledge on the ${\delta}^{13}C_{DIC}$ evolution during $CO_2$ degassing, and therefore it can be utilized in the studies about carbonated water with low pH and the monitoring of geologic carbon sequestration.

pH가 낮은 탄산수의 CO2 탈기에 따른 용존탄소동위원소 변화

채기탁,유순영,김찬영,박진영,방하은,이인혜,고동찬,신영재,오진만 한국지하수토양환경학회 2019 지하수토양환경 Vol.24 No.3

It is known that δ13CDIC (carbon-13 isotope of dissolved inorganic carbonate (DIC) ions) of water increases when dissolved CO2 degases. However, δ13CDIC could decrease when the pH of water is lower than 5.5 at the early stage of degassing. Laboratory experiments were performed to observe the changes of δ13CDIC as CO2 degassed from three different artificial CO2-rich waters (ACWs) in which the initial pH was 4.9, 5.4, and 6.4, respectively. The pH, alkalinity and δ13CDIC were measured until 240 hours after degassing began and those data were compared with kinetic isotope fractionation calculations. Furthermore, same experiment was conducted with the natural CO2-rich water (pH 4.9) from Daepyeong, Sejong City. As a result of experiments, we could observe the decrease of DIC and increase of pH as the degassing progressed. ACW with an initial pH of 6.4, δ13CDIC kept increasing but, in cases where the initial pH was lower than 5.5, δ13CDIC decreased until 6 hours. After 6 hours δ13CDIC increased within all cases because the CO2 degassing caused pH increase and subsequently the ratio of HCO3 − in solution. In the early stage of CO2 degassing, the laboratory measurements were well matched with the calculations, but after about 48 hours, the experiment results were deviated from the calculations, probably due to the equilibrium interaction with the atmosphere and precipitation of carbonates. The result of this study may be not applicable to all natural environments because the pressure and CO2 concentration in headspace of reaction vessels was not maintained constant as well as the temperature. Nevertheless, this study provides fundamental knowledge on the δ13CDIC evolution during CO2 degassing, and therefore it can be utilized in the studies about carbonated water with low pH and the monitoring of geologic carbon sequestration.

Geochemical modeling of CO₂-water-rock interactions for two different hydrochemical types of CO₂-rich springs in Kangwon District, Korea

Choi, B.Y.,Yun, S.T.,Kim, K.H.,Choi, H.S.,Chae, G.T.,Lee, P.K. Elsevier 2014 Journal of geochemical exploration Vol.144 No.1

Naturally outflowing CO<SUB>2</SUB>-rich springs are a natural analogue of the seepage of sequestered CO<SUB>2</SUB> in geological storage sites. In Kangwon district of South Korea, two hydrochemically different types of CO<SUB>2</SUB>-rich springs (i.e., Ca-HCO<SUB>3</SUB>-type and Na-HCO<SUB>3</SUB>-type) occur together in a granitic terrain. Hydrochemical and water-isotope data (i.e., δ<SUP>18</SUP>O-δD and tritium) show that Na-HCO<SUB>3</SUB>-type springs have experienced significant silicate weathering processes over a long residence time at depths, while Ca-HCO<SUB>3</SUB>-type springs were formed by the mixing of Na-HCO<SUB>3</SUB>-type springs with shallow groundwater during ascent. In this study, diverse geochemical models including mixing, ion exchange and reaction path were investigated to verify the geochemical processes accounting for the occurrence of two contrasting types of CO<SUB>2</SUB>-rich springs. The mixing and ion exchange models reveal that Ca-HCO<SUB>3</SUB>-type springs are well explained by reverse cation exchange occurring during the mixing of Na-HCO<SUB>3</SUB>-type springs with shallow groundwater. The Na-HCO<SUB>3</SUB>-type springs are well explained by the reaction path modeling including the dissolution of silicate minerals (plagioclase, K-feldspar and biotite) and the precipitation of secondary minerals (calcite, kaolinite, muscovite and Mg-beidellite), implying that dissolved carbon is sequestered by calcite precipitation (i.e., mineral trapping). However, the concentrations of K in our modeling results are far below those of K observed in Na-HCO<SUB>3</SUB>-type springs, because of the precipitation of muscovite considered in the model, suggesting the partial disequilibrium state of the aquifer during the hydrolysis of K-feldspar under high P<SUB>CO'2</SUB> conditions. This result implies that to better predict long-term CO<SUB>2</SUB>-water-rock interactions in a geological storage site with abundant K-feldspar, the secondary K-bearing minerals should be carefully predicted, because a target aquifer can be far from chemical equilibrium during the storage period. This study shows that geochemical modeling can be effectively used to predict the hydrochemical changes of groundwater during long-term CO<SUB>2</SUB>-water-rock interactions and subsequent leakage toward surface in K-feldspar rich aquifer, although it should be included in a fully coupled computational approach between fluid flow, heat transfer and reactive mass transport processes in the future research.

제주도 현무암에 포획된 페리도타이트에 산출되는 맨틀 기원의 CO₂-유체포유물

서민영(Minyoung Seo),우용훈(Yonghoon Woo),박근영(Geunyeong Park),김은주(Eunju Kim),임현수(Hyoun Soo Lim),양경희(Kyounghee Yang) 한국암석학회 2016 암석학회지 Vol.25 No.1

제주도 현무암에 산출되는 첨정석 페리도타이트 포획암에 CO₂-유체포유물이 포획되어 있다. 이 CO₂-유체포유물들은 규칙적인 결정면으로 둘러싸여 있으며 세립의 네오블라스트 결정에는 일차포유물로, 조립의 반상쇄성에는 이차포유물로 산출된다. 냉각/가열 실험에서 CO₂-유체포유물의 삼중점은 -57.1℃(±0.9℃)로서 대체로 균질하다. 이는 이 CO₂-유체포유물들이 거의 순수하게 CO₂로 이루어져 있음을 의미한다. 그러나 균질화 온도는 -39℃(ρ=1.12 g/㎤))에서 23oC(ρ=0.82 g/㎤))로 넓은 범위에 걸쳐 나타나며, 이는 많은 유체포유물이 포획된 이후 재평형 되어졌음을 반영한다. 일차/이차포유물과 균질화온도 사이에 체계적인 차이는 없다. 가장 낮은 균질화온도(즉, 가장 높은 밀도)를 보이는 유체포유물에서 계산된 포획 압력은 ≈0.9 ㎬이다. 제주 페리도타이트와 CO₂-유체포유물의 조직적 특성과 낮은 균질화 온도는 CO₂-유체가 맨틀기원의 유체로서 상부 맨틀암석권에서 페리도타이트의 재결정화 작용 동안 존재하던 유체로 해석된다. CO₂-유체의 포획은 제주 페리도타이트의 진화과정에서 후기의 사건이며, 상부맨틀 암석권의 상부(천부)에서 일어났음을 지시하고 있다. Negative crystal shaped CO₂-rich fluid inclusions, trapped as primary inclusions in neoblasts and as secondary inclusions in porphyroblasts, were studied in spinel peridotite xenoliths from Jeju Island. Based on microthermometric experiments, the solid phase melts at -57.1℃(±0.9℃) with no other observable melting events, indicating that the trapped fluid is mostly CO₂. The homogenization temperatures show a much wider range from -39℃(ρ=1.12 g/㎤)) to 23oC(ρ=0.82 g/㎤)), suggesting that most of the inclusions (originally trapped at mantle conditions) re-equilibrated to lower density values. Nevertheless, the highest density CO₂ in our fluid inclusions is consistent with entrapment of fluids at upper mantle pressures (and depths). The calculated trapping pressure from CO₂-rich fluid inclusions that appear to be free from re-equilibrium, e.g., showing the lowest homogenization temperatures, is ≈0.9 ㎬. Based on the petrographic evidences, the fluid entrapment can be regarded as a late stage event in the evolution of the shallow lithospheric mantle.

Analysis of a rich vapor compression method for an ammonia-based CO₂ capture process and freshwater production using membrane distillation technology

Ullah, Asad,Soomro, Mujeeb Iqbal,Kim, Woo-Seung Elsevier 2019 Chemical engineering research & design Vol.147 No.-

<P><B>Abstract</B></P> <P>Post-combustion capturing of CO<SUB>2</SUB> through chemical solvent absorption is a promising technique for reducing the CO<SUB>2</SUB> emissions from fossil fuel power plants. However, the energy penalty associated with the absorbent regeneration continues to be a critical challenge in the chemical solvent absorption process. In this study, the operating parameters of ammonia-based CO<SUB>2</SUB> capture were optimized to reduce the energy penalty. This optimized process was considered a base process to which process modifications were added, with the goal of further reducing the energy consumption. These process modifications included absorber inter-cooling and rich vapor compression (RVC) combined with cold solvent split (CSS) processes. The combined RVC and CSS process was compared with the base process and advanced NH<SUB>3</SUB>-based CO<SUB>2</SUB> capture processes, such as the rich split process and the inter-heating process. Compared to the base process, the combined process reduced the energy requirements by 20.2%, which was higher than the 11.6% and 8.26% energy reductions obtained via the rich split and inter-heating processes, respectively. The combined process was also compared with MEA-based process modifications. The energy savings from the combined process were higher than those of the MEA-based process modifications. To estimate the trade-offs between the energy savings resulting from the combined process vs. the capital cost of the additional equipment required, the Aspen Capital Cost Estimator (ACCE) was used. The results showed that the combined process saved $0.707 million per year. Furthermore, a membrane distillation (MD) technology was integrated with the CO<SUB>2</SUB> capture unit to produce freshwater. This additional process produced freshwater at a rate of 719.240 m<SUP>3</SUP>/day at a feed stream temperature to the MD unit of 35.66 ℃.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Process modifications were proposed for NH<SUB>3</SUB>-based CO<SUB>2</SUB> capture process. </LI> <LI> RVC combined with CSS process can reduced the reboiler duty by 20.2%. </LI> <LI> Intercooling process can reduce the absorber packing height by 25%. </LI> <LI> RVC combined with CSS process can save $0.707 million from the total cost per year. </LI> <LI> The freshwater was produced at a rate of 719.240 m<SUP>3</SUP>/day at feed temperature of 35.66 ℃ to the MD unit. </LI> </UL> </P>