• Journal of the Korean Electrochemical Society
• /
• v.24 no.3
• /
• pp.42-51
• /
• 2021

Dissociation into Lithium-polysulfide electrolyte due to repeated cycles during the Lithium/Sulfur battery reaction is a major problem of reduced battery lifespan. We searched for a porous carbon with a large specific surface area that infiltrated S to prevent liquid Lithium-polysulfide from being dissolved in electrolyte, induce adsorption of Lithium-polysulfide, and further increase conductivity. In order to obtain porous carbon spheres with a large specific surface area, the carbon spheres of 1939 m²/g were raised to 2200 m²/g through additional KOH treatment. In addition, through heat treatment with S, a carbon sulfur compound containing 75 wt% of S was fabricate and material analysis was conducted on the possibility of using the cathode material. The electrochemical characteristics of the Reference (622; sulfur: 60%, conductive material: 20%, binder: 20%) pouch cell and the pouch cell made using 75wt% of carbon sulfur compound were analyzed. 75wt% of carbon sulfur pouch cell showed a 20% increase in lifespan and 10% improvement in C-rate compared to the Reference pouch cell after 50 cycles.

• International Journal of Computer Science & Network Security
• /
• v.22 no.3
• /
• pp.37-44
• /
• 2022

Plug-in Hybrid electric vehicles (PHEV) show great potential to reduce gas emission, improve fuel efficiency and offer more driving range flexibility. Moreover, PHEV help to preserve the eco-system, climate changes and reduce the high demand for fossil fuels. To address this; some basic components and energy resources have been used, such as batteries and proton exchange membrane (PEM) fuel cells (FCs). However, the FC remains unsatisfactory in terms of power density and response. In light of the above, an electric storage system (ESS) seems to be a promising solution to resolve this issue, especially when it comes to the transient phase. In addition to the FC, a storage system made-up of an ultra-battery UB is proposed within this paper. The association of the FC and the UB lead to the so-called Fuel Cell Battery Electric Vehicle (FCBEV). The energy consumption model of a FCBEV has been built considering the power losses of the fuel cell, electric motor, the state of charge (SOC) of the battery, and brakes. To do so, the implementing a reinforcement-learning energy management strategy (EMS) has been carried out and the fuel cell efficiency has been optimized while minimizing the hydrogen fuel consummation per 100km. Within this paper the adopted approach over numerous driving cycles of the FCBEV has shown promising results.

• 한국전기화학회:학술대회논문집
• /
• 1998.12a
• /
• pp.7-27
• /
• 1998

In order to design capacity of lithium ion battery, some calculations were carried out based on the characteristics of materials by the given battery shape and dimension. The principle of design was built by the interpretation of the correlation of material, electrochemical and battery factors. Parameters of materials are fundamental physical properties of constituent such as cathode. separator, anode, current collectors and electrolyte. Electrochemical factor includes potential pattern as a function of specific capacity, specific discharge capacity(or initial irreversible specific capacity or Ah efficiency) as a function of specific charge capacity and material balancing. Parameters of battery are dimension, construction hardware and performance. Battery capacity was simulated for a lithium cobalt dioxide as cathode and a hard carbon as anode to achieve 1100 mAh for the charge limit voltage of 4.2V, the weight ratio(+/-) of 2.4 and ICR18650. A fabricated test cell (ICR18650) which have weight ratio(+/-) of 2.4 discharged to 1093 mAh for the charge limit voltage of 4.2V. The sequential discharge capacity show good correspondence with designed capacity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.10a
• /
• pp.882-883
• /
• 2013

With the development of the society, pure electric vehicles will be surely important of the future. Electric vehicle requires various technology like motor driving, battery management, operational efficiencies and so on. Battery management is indeed the most important to enhance battery's performance and life. This paper has deeply discussed and studied on the lithium-polymer battery management system of pure electric vehicle. First of all we have analyzed the characteristic of the lithium-polymer batteries and the factors influenced on the state of charge. Then a logical SOC measuring method has been raised, which is the combination of open circuit voltage and Ah integration. The next we will introduce the design of battery management system, the battery management system performs many functions, such as inspecting the whole process, when it's running cell equalization protecting and diagnosing the battery, estimating the state of charge. The module design style including microcontroller, data aquisition module, charging control module and serial communication module. To arrive at conclusions, the battery management system which this paper has introduced is reliable and economical.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.19 no.6
• /
• pp.113-118
• /
• 2011

Fuel Cell Hybrid Vehicle (FCHV) is one of the most promising candidates for the next generation of transportation. It has many outstanding advantages such as higher energy efficiency and much lower emissions than internal combustion engine vehicles. It also has the ability of recovering braking energy. In order to design an FCHV drive train, we need to determine the size of the electric motor, the Fuel Cell System (FCS), and the battery. In this paper, the methodology for the sizing of these components is introduced based on the driveability constraints of the FCHV. A power management strategy is also presented because the battery energy capacity depends on it. The warm-up time of the FCS is also considered in the power management strategy and the simulation result is compared to that without considering the warm-up time.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.33 no.2
• /
• pp.113-118
• /
• 2005

This paper shows a satellite battery cell voltage monitor system to make differential voltage measurements when one or both measurement points are beyond voltage range allowed by a conventional differential amplifier. This system is particularly useful for monitoring the individual cell voltage of series-connected cells that constitute a rechargeable satellite battery in which some cell voltages must be measured in the presence of high common mode voltage.

• Proceedings of the KIPE Conference
• /
• 2019.11a
• /
• pp.70-72
• /
• 2019

For the safe and reliable operation of Lithium-ion batteries in Electric Vehicles (EVs) or Energy Storage Systems (ESSs), it is essential to have accurate information of the battery such as State of Charge (SOC). Many kinds of different techniques to estimate the SOC of the batteries have been developed so far such as the Kalman Filter. However, when it is applied to the multiple number of batteries it is difficult to maintain the accuracy of the estimation over all cells due to the difference in parameter value of each cell. Moreover the difference in the parameter of each cell may become larger as the operation time accumulates due to aging. In this paper a novel Deep Neural Network (DNN) based SOC estimation method for multi cell application is proposed. In the proposed method DNN is implemented to learn non-linear relationship of the voltage and current of the lithium-ion battery at different SOCs and different temperatures. In the training the voltage and current data of the Lithium battery at charge and discharge cycles obtained at different temperatures are used. After the comprehensive training with the data obtained with a cell resulting estimation algorithm is applied to the other cells. The experimental results show that the Mean Absolute Error (MAE) of the estimation is 0.56% at 25℃, and 3.16% at 60℃ with the proposed SOC estimation algorithm.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.5
• /
• pp.1454-1470
• /
• 2014

This paper propose a new power conditioner topology with intelligent power management controller that integrates multiple renewable energy sources such as solar energy, wind energy and fuel cell energy with battery backup to make best use of their operating characteristics and obtain better reliability than that could be obtained by single renewable energy based power supply. The proposed embedded controller is programmed for maintaining a constant voltage at PCC, maximum power point tracking for solar PV panel and WTG and power flow control by regulating the reference currents of the controller on instantaneous basis based on the power delivered by the sources and load demand. Instantaneous variation in reference currents of the controller enhances the controller response as it accommodates the effect of continuously varying solar insolation and wind speed in the power management. The power conditioner uses a battery bank with embedded controller based online SOC estimation and battery charging system to suitably sink or source the input power based on the load demand. The simulation results of the proposed power management system for a standalone solar/WTG/fuel cell fed hybrid power supply with real time solar radiation and wind velocity data collected from solar centre, KEC for a sporadically varying load demand is presented in this paper and the results are encouraging in reliability and stability perspective.

• Proceedings of the KIEE Conference
• /
• 2003.04a
• /
• pp.182-185
• /
• 2003

Lithium ion battery is required to balance cells in order to minimize the electric capacity difference between the batteries. This paper proposes a cell balancing method by using inductor. Simulation and experimental results are presented.

• Proceedings of the KIPE Conference
• /
• 2004.07b
• /
• pp.501-505
• /
• 2004

The study on the hybrid power source for the IMT2000 application has been presented. The hybrid power source is composed of solar cell, super-capacitor and battery. To compensate for the pulse loader of the IMT2000 application, the super-capacitor is connected through the Lithium-ion battery to absorb the pulse current. The solar cell provides the additional current to compensate for the depleted current. The controller design for the hybrid source has been presented and verified through experiment.