• Macromolecular Research
• /
• v.16 no.2
• /
• pp.134-138
• /
• 2008

A novel acrylol borate was designed and synthesized by reacting acrylate monomer and boric acid. The obtained acrylol borate was used as both gelator and anion receptor for the liquid electrolyte in a lithium secondary battery. It was found that the ionic conductivity of the gel polymer electrolyte (GPE) was as high as that of the liquid electrolyte, and the thermal stability of GPE was increased when only 2 wt% acrylol borate was incorporated into the liquid electrolyte. These results suggest that acrylol borate can be used as an effective additive to enhance the thermal stability of the electrolyte without adversely affecting its conductivity. It is believed that the strong complex formation between boron in the gelator and the anion of the salt is responsible for the enhanced thermal stability of the electrolyte solution and the increased ionic conductivity.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.21 no.6
• /
• pp.49-57
• /
• 2013

In this study, we fabricated a parallelly connected Li-ion battery/supercapacitor hybrid cell to combine the advantageous characteristics of Li-ion battery and supercapacitor, high energy density and high power density, respectively, and investigated its discharging characteristics over a wide temperature range from -40 to $25^{\circ}C$. At the initial state of discharging of the hybrid cell, the power was mostly provided by the supercapacitor and then the portion of the Li-ion battery was gradually increased. By installing a switching system into the hybrid cell, which controls the discharging sequence of Li-ion battery and supercapacitor, the maximum power was improved by 40% compared with non switching system. In addition at low temperatures, the power and discharging time of the hybrid cell were significantly enhanced compared to a battery-alone system. The hybrid cell is expected to be applied in electric vehicles and small domestic appliances that require high power at initial discharging state.

• Membrane Journal
• /
• v.14 no.4
• /
• pp.263-274
• /
• 2004

The polymeric membrane, a component of battery devices such as Li-ion battery (LIB) and Li-polymer battery (LPB), is a typical material in which the carrier mobility dominates the battery performance. In this paper, the state-of-the-art of membranes for secondary battery is described in terms of membrane properties. Several prerequisites, which are related to stability of battery devices, are discussed to design and prepare suitable polymeric membranes. In addition, physical requirements of membranes and their measurement methods are described to develop applicable polymeric membranes in membrane preparation processes.

• Proceedings of the KIPE Conference
• /
• 2004.07a
• /
• pp.82-86
• /
• 2004

In this paper, a cycler system for the Lithium-Polymer battery with the large capacity of 120Ah is presented. This system is constituted as the two units for the charging and discharging. The Lithium-Polymer battery should be charged in CC and CV mode, and it is required a very high precision control of the voltage and current for the charging unit. To decrease the switching noises and harmonics, parallel operation method is adopted and utilized in the power conversion module. The discharging unit has a link AC system function to return the discharging energy of battery to AC line and has comparatively less thermal loss. These units are designed to be controlled and monitored by personal computer. The total system for the battery charging and discharging is described and presented.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.17 no.6
• /
• pp.532-538
• /
• 2012

This paper proposes the Mathematical Modeling for HEV High-power Lithium-Polymer Battery. The nonlinear system of the Lithium Battery electrical characteristic express mathematical state equation. We also test charge/discharge and temperature experimental used to identify parameters of the cell find parameter of the least error. The proposed model experimental results is used with battery cycler to verify of the proposed model.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.5 no.5
• /
• pp.435-442
• /
• 2000

Started upon Its discovery by Wright et al in 1773, studies on the solid polymer electrolyte are being carried out vigorously. So, models of Li-polymer battery have been developed through R-L-C components combination and PSpice functional block in this parer. The impedance characteristics of Li-polymer battery with R-L-C components are presented. Simulation results using PSpice functional model are compared with measured charge/discharge characteristics. Also, as to the number of cycle(charge/discharge), coulomb efficiency of Li-polymer is evaluated through experimental results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.05c
• /
• pp.88-90
• /
• 2003

The purpose of this study is to research and develop tin oxide-flash composite for lithium Ion polymer battery. Tin oxide is one of the promising material as a electrode active material for lithium Ion polymer battery (LIPB). Tin-based oxides have theoretical volumetric and gravimetric capacities that are four and two times that of carbon, respectively. We investigated cyclic voltammetry and charge/discharge cycling of SnO-flyash/SPE/Li cells. The first discharge capacity of SnO-flyash composite anode was 720 mAh/g. The discharge capacity of SnO-flyash composite anode 412 and 314 mAh/g at cycle 2 and 10 at room temperature, respectively. The SnO-flyash composite anode with PVDF-PMMA-PC-EC-$LiClO_4$ electrolyte showed good capacity with cycling.

• Journal of the Korean Electrochemical Society
• /
• v.7 no.4
• /
• pp.189-193
• /
• 2004

Lithium secondary battery with gel polymer electrolyte, which was composed of POAGA and TEGDMA, was prepared and its cell performances were evaluated. Collation time decreased with increasing the contents of the monomer in the POAGA-based gel polymer electrolyte. The polymer electrolyte was stable up to 4.5V electro-chemically and its ionic conductivity was $5.2\times10^{-3}Scm^{-1}$ at room temperature. The lithium-ion polymer battery with $3.0wt\%$ curable monomer and $1.0wt\%$ monomer showed rate-capability, low-temperature performance and cycleability.

• Proceedings of the KIEE Conference
• /
• 1999.11d
• /
• pp.968-970
• /
• 1999

The trend of increasing of portable electric devices and demand for global environmental conservation have demands the development of high energy density rechargeable batteries. Lithium polymer battery has excellent theoretical energy density and energy conversion efficiency. Lithium polymer battery, included solid polymer electrolyte(SPE), can be viewed as a system suitable for wide applications from thin film batteries for microelectronics to electric vehicle batteries. The purpose of this paper is to research and development of flyash anode for lithium polymer battery. We investigated AC impedance response and charge/discharge characteristics of flyash/SPE/Li cells. The radius of semicircle associated with the interfacial resistance of flyash/SPE/Li cell increased very slowly during discharge process from 3.11V to 0.478V. And then the cell resistance was decreased at discharge process from 10% SOC to 0% SOC. Also, The radius of semicircle associated with the interfacial resistance of flyash/SPE/Li cell decreasing very slowly during charge process. And then the cell resistance was increased after 20th discharge precess. The discharge capacity based on flyash of 1st and 20th cycles was 276mAh/g and 143mAh/g.

• Macromolecular Research
• /
• v.9 no.5
• /
• pp.292-295
• /
• 2001

A cross-linked solid polymer electrolyte was prepared by copolymerizing photochemically acrylonitrile (AN), oligo(ethylene glycol ethyl ether) methacrylate, oligo(ethylene glycol) dimethacrylate in the presence of lithium perchlorate as a lithium salt, ethylene carbonate-propylene carbonate as a mixed plasticizer, and poly(ethylene oxide) as a polymer matrix. The maximum ionic conductivity of the polymer electrolyte was 2.35$\times$10$\^$-3/ S/cm. The interface resistance of the polymer electrolyte was very low compared to that of the polymer electrolyte without AN. The former electrolyte was stable up to 4.3 V and the Ah efficiency was nearly 100% during the charge-discharge cycle.