Development of LiFePO₄/FePO₄ Electrode for Electro-Osmotic Pump using Li⁺ Migration

Baek, Jaewook,Kim, Kyeonghyeon,Shin, Woonsup The Korean Electrochemical Society 2018 Journal of electrochemical science and technology Vol.9 No.2

Olivine structure of $LiFePO_4$ (LFP) is one of the most commonly used materials in aqueous rechargeable lithium batteries (ARLBs), and can store and release charge through the insertion/de-insertion of $Li^+$ between LFP and FP. We have fabricated LFP and LFP/FP electrodes on titanium paper and studied their electrochemical properties in 2 M $Li_2SO_4$. The LFP/FP electrode was determined to be a suitable electrode for electo-ostmotic pump (EOP) in terms of efficiency in water and 0.5 mM $Li_2SO_4$ solution. Experiments to determine the effect of cations and anions on the performance of EOP using LFP/FP electrode have shown that $Li^+$ is the best cation and that the anion does not significantly affect the performance of the EOP. As the concentration of $Li_2SO_4$ solution was increased, the current increased. The flow rate peaked at $4.8{\mu}L/30s$ in 1.0 mM $Li_2SO_4$ solution and then decreased. When the EOP was tested continuously in 1.0 mM $Li_2SO_4$ solution, the EOP transported approximately 35 mL of fluid while maintaining a stable flow rate and current for 144 h.

전고체 전지 장기 수명 개선을 위한 NCM/LFP 블랜딩 양극 물질 최적화 연구

송영웅(Youngwoong Song),김민영(Minyoung Kim),허국진(Kookjin Heo),황다희(Dahee Hwang),이종관(Jongkwan Lee),김재국(Jaekook Kim),임진섭(Jinsub Lim) 한국전지학회 2021 한국전지학회지 Vol.1 No.1

본 논문에서 층상구조의 NCM70과 올리빈 구조의 LiFePO4를 다양한 비율로 혼합하여 제조된 블랜딩 양극 물질의 전기화학적 특성을 보고한다. XRD 분석을 통해 블랜딩 양극 물질은 NCM과 LFP 구조가 혼합된 상으로 존재함을 확인하였다. 산화물계 무기 고체 전해질과 고분자 고체 전해질이 결합된 복합 고체전해질을 이용하여 전고체 전지를 제조하여 실험을 진행한 결과, NCM70의 사이클 특성을 LFP와 블랜딩을 통해 향상시킬 수 있다. We report the electrochemical properties of blended cathode materials prepared by mixing layered structure NCM70 and olivine structure LiFePO4 by various ratios. Through XRD analysis, it was confirmed that the blending cathode material exists as a mixed phase of NCM and LFP structures. As results of the systematic experiment by manufacturing an all-solid-state lithium battery (ASLB) using a composite solid electrolyte in which an oxide-based inorganic solid electrolyte and a polymer solid electrolyte were combined, it was possible to improve the deterioration phenomenon occurring during the cycle of NCM70 by blending with LFP.

기계화학적 방법을 이용한 폐LFP배터리 양극재분말로부터 선택적 리튬 회수 연구

김보람,김희선,김대원 한국자원리싸이클링학회 2023 資源 리싸이클링 Vol.32 No.4

Globally, there is a rapid increase in the demand for electric vehicles due to the support for the widespread adoption of electric cars through greenhouse gas regulations in response to climate change. This has resulted in an increase in battery production, which in turn leads to future concerns regarding the disposal of used batteries. In this study, lithium was recoverd preferentially from the cathode material of discarded LFP(LiFePO4) batteries. We conducted the extractions of lithium in 2 ways. One is the conventional leaching method which was reacted with sodium persulfate (Na2S2O8) aqueous solution. The other is the mechanochemical method which was milled with sodium persulfate powder, followed by water leaching with distilled water. We compared and analyzed the leaching efficiency and characteristics of the major elements using these two methods. In the conventional leaching method, the solid-liquid ratio was set as a variable, and in the mechanochemical leaching method, the amount of hydrogen peroxide(H2O2) was used as a variable. In both methods used in this study, lithium could be pre-leached from about 90% to 100%, and the selectivity of lithium could be improved by controlling the leaching of iron by adding hydrogen peroxide.

Effects of Posture and Acute Sleep Deprivation on Heart Rate Variability

남기창,김덕원,Min Kyung Kwon 연세대학교의과대학 2011 Yonsei medical journal Vol.52 No.4

Purpose: In our previous study to investigate autonomic nervous system (ANS) activity due to radio frequency (RF) radiation using heart rate variability (HRV), drowsiness was observed in approximately half of all subjects. Therefore, the usage of HRV with unwanted drowsiness could falsely indicate the effects of RF radiation by mobile phones on the ANS. The objective of this study was to determine which posture is appropriate for accurate HRV analysis for provocation study. Materials and Methods: A total of 52 healthy subjects (25 males and 27 females)participated in this experiment. We measured the number of times a subject showed drowsiness or sleep deprivation due to awakening, and analyzed HRV six times over 30 minutes in sitting and recumbent postures, using power spectrum. Results: We employed the ratio of low frequency power to high frequency power (LFP/HFP) to analyze the changes in the ANS. The number of sleep deprivation occurrences in the sitting posture was significantly less than that in the recumbent posture (p<0.01), resulting in smaller increase of LFP/HFP. Although LFP/HFP of the two postures varied with time without any provocation, it was more stable in sitting than in recumbent postures. Conclusion: A sitting posture is preferable to a recumbent posture for analyzing HRV, because of decreased drowsiness and sleep deprivation, thereby decreasing variation of LFP/HFP during experiment. Considering the drowsiness, it is also recommended that any experiment should be completed within 15 minutes, if possible.

Numerical Study on Thermal Runaway in LFP/NCM Cylindrical Lithium-Ion Batteries Using 2D Model

Myung Bo Gang,Woo Young Kim,Nam Jin Kim 한국신재생에너지학회 2022 AFORE Vol.2022 No.9

구기자를 첨가한 쿠키의 품질특성과 항산화효과

박복희,조희숙,박선영 한국조리과학회 2005 한국식품조리과학회지 Vol.21 No.1

The purpose of this study was to investigate the antioxidative effect and quality characteristics of cookies made with Lvcii fructus powder(LFP). The cookies were stored at 50 ℃ for 40 days. The LFP additive increased the moisture, ash, crude protein and volume of the cookies. When LFP was added at 5% into the cookies, the spread ratio was higher than for the control, the 10% and the 20% LFP cookies. As more LFP was added, the L-value decreased, and the a--values and b-values increased for thecolor values. For the textural characteristics, springiness and cohesiveness of the control cookies were the highest among the samples, the other side, brittleness and gwemwness were higher in cookies made with LFP than in the control cookies. Overall, the cookies made with 5% LFP were preferred more than the other cookies, as tested forby sensory evaluation. The cookies made with LFP contained mostly palmitic acid (C16:0) followed by oleic acid (C18:1) and stearic acid (CI8:0). The acid value, peroxide value, and thiobarhituric acid value were lower in cookies made with 5% and 10% LFP than in those cookies made with 20% LFP and the control cookies.

동일 형태의 NCM/LFP 배터리의 열폭주 현상에 대한 수치해석적 비교 연구

강명보,김우영,김남진 한국 지열 · 수열에너지학회 2022 한국지열에너지학회논문집 Vol.18 No.4

In this study, the thermal runaway of NCM and LFP batteries were compared and analyzed through numerical analysis under various conditions. Comparing the thermal runaway of the NCM622 (18650) battery cell and the LFP (18650) battery cell through oven test simulation, the LFP battery did not show thermal runaway, whereas the NCM622 battery temperature increased to 710°C in 12 minutes. To observe the thermal runaway and propagation of the prismatic LFP battery cell, the internal temperature was set at 200°C and the oven test simulation was conducted. It was found that thermal runaway occurred at 391°C after 47 minutes. As a result of observing thermal runaway propagation by placing five NCM622 and LFP battery cells, the thermal runaway propagation was clearly observed in the case of the NCM622 battery, but in the case of the LFP battery, thermal runaway was not observed after the first cell. From the third battery cell, it was confirmed that the temperature change was very insignificant, and through this, it is considered that the LFP battery is relatively safe compared to the NCM battery in terms of the thermal runaway propagation of the battery.

구기자 분말이 첨가된 유과의 품질특성 및 항산화효과

박복희(Bock-Hee Park),양효현(Hyo-Hyun Yang),조희숙(Hee-Sook Cho) 한국식품영양과학회 2012 한국식품영양과학회지 Vol.41 No.6

유과의 저장성 향상과 기능성 효과가 있는 소재를 개발하기 위하여 구기자 분말( Lycii fructuspowder)을 첨가한 유과를 제조하여 50℃에서 40일 동안 저장하면서 유과의 저장과정 중 항산화효과와 품질특성을 조사한 결과는 다음과 같다. 구기자 첨가 유과 중 구기자 5% 첨가 유과의 밀도와 부피가 가장 높게 나타났고 대조군에 비해 구기자 첨가 유과의 퍼짐성과 수분함량이 더 많이 증가하였다. 색도에서 구기자 첨가량이 많을수록 L값은 낮게, a값과 b값은 높게 나타났으며 조직감은 구기자 함량이 증가할수록 높게 나타났다. 구기자 유과의 관능평가에서는 유과의 색, 맛, 풍미, 조직감에서 구기자 5% 첨가 유과가 가장 높은 점수를 보였으며 대조군이 전반적인 기호도에서는 가장 낮은 점수를 나타냈다. 저장 기간 중 구기자 유과의 산가를 살펴보면 저장기간이 경과함에 따라 모든 실험군에서 유의적으로 증가하였고 대조군보다 구기자 첨가군에서 훨씬 낮았으며 구기자 5% 첨가 유과에서 가장 낮은 산가를 나타냈다. 과산화물가는 저장 20일까지는 약간씩 증가하다가 그 후 30일까지는 급격히 증가하다가 감소하는 경향을 보였으며 과산화물가 역시 구기자 5% 첨가 유과에서 가장 낮은 과산화물가를 나타냈다. TBA가는 대조군에 비해 구기자 첨가군이 낮은 값을 나타내 지방의 산화를 지연시켰음을 알 수 있었으며, 항산화 활성이 뛰어난 것을 확인할 수 있었다. 이와 같은 결과로부터 구기자 분말을 유과에 첨가 제조 시 저장성 향상과 기능성 효과를 갖는 소재로써의 가능성이 확인되었다. The purpose of this study was to investigate the quality characteristics and antioxidative effect of Yukwa prepared with Lycii fructuspowder (LFP). The Yukwaswere stored at 50oC for 40 days. Yukwadough prepared with 5% LFP demonstrated higher pH and density value compared to the other groups and control. For color values, as more LFP was added, the L-value decreased, whereas the a-value and b-value increased. The hardness of Yukwamade with 7% LFP was the highest among all samples. The results of a sensory evaluation test showed that Yukwaswith 5% LFP was most preferable in terms of overall acceptability compared to the others. The acid, peroxide, and thiobarbituric acid values were lower in Yukwaprepared with 5% LFP compared to Yukwa prepared with 3% or 7% LFP, as well as control Yukwa.

열처리 및 기계화학적 처리를 통한 폐LFP 배터리로부터 가용성 리튬으로의 전환 연구

김보람,김희선,김대원 한국자원리싸이클링학회 2024 資源 리싸이클링 Vol.33 No.3

전 세계적으로 탄소 중립 전략에 따른 탈탄소화와 관련하여 전기자동차의 수요가 급증하고 있다. 전기자동차의 주요 부품인 리튬이온배터리의 수요 또한 급증하게 되었고, 이는 폐배터리의 발생으로 이어진다. 이에 폐배터리를 재활용하여 유가 금속을 회수하기 위한 연구가 수행되고 있으며, 본 연구에서는 폐LFP 배터리의 양극재로부터 리튬을 선택적으로 선침출 및 회수하고자 하였다. 양극재 분말 내 포함된 바인더를 제거하여 반응 표면적 증대 및 반응성을 높이기 위하여 대기 및 질소 분위기 그리고 다양한 온도 범위에서 열처리하였고, 이후 기계화학적(Mechanochemical) 공정을 통하여 수침출 하였다. 먼저, 열처리 후 분말을 과황산나트륨(Na2S2O8)과 기계화학적 반응을 이용하여 가용성 리튬화합물로 전환하였고, 이후 증류수를 이용하여 수침출 하였다. 본 연구에서 열처리를 통한 양극재 분말의 특성변화를 확인하였고, 최종 질소 분위기에서 열처리하여 모든 온도 범위에서 리튬의 침출율은 약 100%로 선침출할 수 있었다. Globally, the demand for electric vehicles (EVs) is surging due to carbon-neutral strategies aimed at decarbonization. Consequently, the demand for lithium-ion batteries, which are essential components of EVs, is also rising, leading to an increase in the generation of spent batteries. This has prompted research into the recycling of spent batteries to recover valuable metals. In this study, we aimed to selectively leach and recover lithium from the cathode material of spent LFP batteries. To enhance the reaction surface area and reactivity, the binder in the cathode material powder was removed, and the material was subjected to heat treatment in both atmospheric and nitrogen environments across various temperature ranges. This was followed by a mechanochemical process for aqueous leaching. Initially, after heat treatment, the powder was converted into a soluble lithium compound using sodium persulfate (Na2S2O8) in a mechanochemical reaction. Subsequently, aqueous leaching was performed using distilled water. This study confirmed the changes in the characteristics of the cathode material powder due to heat treatment. The final heat treatment in a nitrogen atmosphere resulted in a lithium leaching efficiency of approximately 100% across all temperature ranges.

사용 후 LFP(LiFePO₄)로부터 탄산리튬 제조 연구

왕제필 ( Jei-pil Wang ),김재흥 ( Jae-heung Kim ),고민석 ( Min-seok Go ),신민용 ( Min-yong Shin ),이동헌 ( Dong-hun Lee ) 한국폐기물자원순환학회(구 한국폐기물학회) 2021 한국폐기물자원순환학회 춘계학술발표논문집 Vol.2021 No.-

본 연구에서는 LFP(LiFePO₄)로부터 탄산리튬을 회수하기 위해 황산 침출 후 CO₂ 열반응을 통해 탄산리튬을 제조하였다. LFP 10g을 H₂SO₄ 50ml에 장입하여 60분간 반응시켰다. 이때 H₂SO₄의 농도는 0.5, 1, 2M로 변화시켜 실험을 진행하였다. 반응이 끝난 용액은 감압여과를 실시하였으며 여과 후 용액은 400℃에서 3시간 건조하였다. 건조가 끝난 산물은 활성탄과 1:1 비율로 혼합하여 900℃, CO_2(g) 300cc/min에서 3시간 반응하였다. 반응 후 산물은 증류수와 1:30의 고액비로 수침출 및 감압여과를 진행하여 탄산리튬 용액과 불순물을 분리하였다. 회수한 탄산리튬 용액은 200℃에서 24시간 건조하여 탄산리튬 분말을 제조하였다. 탄산리튬 분말은 XRD 및 ICP 분석을 실시하였다.