Cell for X-Ray investigation of new materials for Li-ion batteries
Li-ion batteries are commonly used in our everyday life. However, we face several problems with their applications such as aging of the material inside, necessity of specific charge and discharge cycles, low capacity and small temperature range. In order to overcome these difficulties we have to understand what is happening with the material inside the battery. The solution to the problem is constructing a special experimental cell for X-Ray experiments, which would allow us to measure in-situ battery characteristic.
Our experimental setup consists of two parts. First part is electronics, which allows measuring desired characteristics such as battery capacity, volt-ampere characteristic by charging and discharging the battery repetitively. Control unit of the electronic part is based on AVR microcontroller ATmega 2560 with 10-bit analog to digital converter. It allows having up to 120 measurements per minute with 2 mV and 1 mA accuracy. Control of the power circuit is realized via 8-bit external multichannel digital to analog converter. In addition, there is on-board USB-COM Bridge for communication with specially designed computer software. This software provides control of work regimes. Main functions are charge or discharge of the battery, measurement of capacity, measurement of the level of charge, cycling the battery with specific current in needed range of voltage and charge or discharge to specific capacity.
The second part is a special cylindrical cell consisting of two parts with thin replaceable conducting and X-Ray transparent windows. One part is made from aluminum for cathode material and the other one is made from copper for anode material. They are separated with PTFE gasket. The design of cell allows to conduct XAS, XRD and other types of synchrotron and free electron laser experiments.