| 1. |
- Li, Meiying, et al.
(författare)
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An Improved Test Method of LiFePO4/Graphene Hybrid Cathode Lithium-Ion Battery and the State of Charge Estimation
- 2021
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Ingår i: Journal of Electrochemical Energy Conversion and Storage. - : ASME International. - 2381-6872 .- 2381-6910. ; 18:1
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Tidskriftsartikel (refereegranskat)abstract
- The state of charge (SoC) of the battery is a typical characterization of the operating state of the battery and criterion for the battery management system (BMS) control strategy, which must be evaluated precisely. The establishment of an accurate algorithm of SoC estimation is of great significance for BMS, which can help the driver judge the endurance mileage of electric vehicle (EV) correctly. In this paper, a second-order resistor-capacity (RC) equivalent circuit model is selected to characterize the electrical characteristics based on the electrochemical model of the LiFePO4/graphene (LFP/G) hybrid cathode lithium-ion battery. Moreover, seven open circuit voltage (OCV) models are compared and the best one of them is used to simulate the dynamic characteristics of the battery. It is worth mentioning that an improved test method is proposed, which is combined with least square for parameters identification. In addition, the extended Kalman filter (EKF) algorithm is selected to estimate the SoC during the charging and discharging processes. The simulation results show that the EKF algorithm has the higher accuracy and rapidity than the KF algorithm.
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| 2. |
- Li, Yuan, et al.
(författare)
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Comparative Study of the Influence of Open Circuit Voltage Tests on State of Charge Online Estimation for Lithium-Ion Batteries
- 2020
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Ingår i: IEEE Access. - : IEEE. - 2169-3536. ; 8, s. 17535-17547
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Tidskriftsartikel (refereegranskat)abstract
- The accurate state of charge (SoC) online estimation is a significant indicator that relates to driving ranges of electric vehicles (EV). The relationship between open circuit voltage (OCV) and SoC plays an important role in SoC estimation for lithium-ion batteries. To compare with the traditional incremental OCV (IO) test and the low current OCV (LO) test, a novel OCV test which combines IO test with LO test (CIL) is proposed in this paper. Based on the reliable parameters online identification of the dual polarization (DP) battery model, two SoC estimation algorithms are compared on the accuracy, robustness and convergence speed for the entire SoC region. Meanwhile, the comparative study of the three OCV-SoC relationships fits by the corresponding OCV tests is discussed in terms of the SoC online estimation under various temperatures. The results show that the adaptive extended Kalman filter (AEKF) algorithm can better improve the accuracy and robustness of SoC estimation than that of the extended Kalman filter (EKF) algorithm. Most importantly, the OCV-SoC relationship obtains from the CIL OCV test method is applied to the AEKF algorithm, which has higher accuracy and better statistical indices of SoC estimation, especially suitable for the low temperature.
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| 3. |
- Li, Yuan, et al.
(författare)
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Investigation on liquid cold plate thermal management system with heat pipes for LiFePO4 battery pack in electric vehicles
- 2021
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Ingår i: Applied Thermal Engineering. - : Elsevier BV. - 1359-4311 .- 1873-5606. ; 185
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Tidskriftsartikel (refereegranskat)abstract
- An appropriate battery thermal management system is essential for electric vehicles to keep an optimal working temperature range with minimal temperature difference, and meanwhile to ensure the battery is more efficient and safe. In this paper, the liquid cold plate thermal management system with heat pipes is proposed to investigate the thermal characteristic of LiFePO4 battery pack during various discharge rate operations. A three-dimensional numerical model based on standard k-epsilon turbulent model is developed to realize the visible analysis of fluid flow and heat transfer for the proposed thermal management system. The 50 Ah battery module is used in the experiment to validate the cooling effects of proposed thermal management system relied on heat pipes, and its performance is compared with liquid cold plate without heat pipes. Furthermore, the cooling performance of the cold plate with heat pipes could be further improved through the orthogonal experiment design, the maximum temperature of battery cell and temperature difference of battery module could be dropped by 6.95% and 11.08%, as compared with the original design. What's more, the channel height of cold plate with heat pipes has the greatest effect on the maximum temperature of battery cells and temperature difference of battery modules.
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| 4. |
- Fang, Meiying, et al.
(författare)
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Contrasting mode of evolution at a coat color locus in wild and domestic pigs
- 2009
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Ingår i: PLoS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 5:1, s. e1000341-
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Tidskriftsartikel (refereegranskat)abstract
- Despite having only begun ∼10,000 years ago, the process of domestication has resulted in a degree of phenotypic variation within individual species normally associated with much deeper evolutionary time scales. Though many variable traits found in domestic animals are the result of relatively recent human-mediated selection, uncertainty remains as to whether the modern ubiquity of long-standing variable traits such as coat color results from selection or drift, and whether the underlying alleles were present in the wild ancestor or appeared after domestication began. Here, through an investigation of sequence diversity at the porcine melanocortin receptor 1 (MC1R) locus, we provide evidence that wild and domestic pig (Sus scrofa) haplotypes from China and Europe are the result of strikingly different selection pressures, and that coat color variation is the result of intentional selection for alleles that appeared after the advent of domestication. Asian and European wild boar (evolutionarily distinct subspecies) differed only by synonymous substitutions, demonstrating that camouflage coat color is maintained by purifying selection. In domestic pigs, however, each of nine unique mutations altered the amino acid sequence thus generating coat color diversity. Most domestic MC1R alleles differed by more than one mutation from the wild-type, implying a long history of strong positive selection for coat color variants, during which time humans have cherry-picked rare mutations that would be quickly eliminated in wild contexts. This pattern demonstrates that coat color phenotypes result from direct human selection and not via a simple relaxation of natural selective pressures.
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| 5. |
- Li, Shuwei, et al.
(författare)
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Electron uptake from solid electrodes promotes the more efficient conversion of CO 2 to polyhydroxybutyrate by using Rhodobacter sphaeroides
- 2023
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Ingår i: Chemical Engineering Journal. - 1385-8947. ; 469
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Tidskriftsartikel (refereegranskat)abstract
- Microbial electrosynthesis (MES) is a promising strategy for the conversion of CO2 to useful chemicals. Nevertheless, the characteristics of electrode-associated cells in MES and their metabolic pathway regulation in CO2 fixation have not been elucidated. This study examined the electrode-driven polyhydroxybutyrate (PHB) production from CO2 in Rhodobacter sphaeroides. The electron uptake and regulation of the metabolic pathways differed in electrode-associated and suspended R. sphaeroides. The electrode-associated cells produced PHB at concentrations up to 23.50 ± 2.8% of the dry cell weight (DCW), whereas the suspended cells grew faster but with a lower cellular PHB content. Gene expression analyses showed that phaA expression was upregulated in electrode-associated R. sphaeroides, whereas phaB expression was downregulated in suspended cells. The electrode-associated cells expressed unconventional CO2 fixation enzymes, such as isocitrate dehydrogenase and formate dehydrogenase, with more PHB synthesis. These results show that CO2 can be upcycled to polymeric substances and provide novel insights into the genetic regulation of electrode-associated cells in MES.
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