A low-cost approach to on-board electrochemical impedance spectroscopy for a lithium-ion battery: supplementary materials

The folder "Supplementary data" contains the codes used to manage the EIS acquisition and the EIS data obtained in the tests performed in the paper "A low-cost approach to on-board electrochemical impedance spectroscopy for a lithium-ion battery". CODES: 1) The folder Pynq C code contains the C code running on the Pynq Z2 microcontroller with the libraries used to manage two main functions: - to control a custom FPGA layer used to generate a PWM-modulated sinusoidal stimulus signal to inject as a reference signal in the current control loop of a DC/DC converter, which is used as a sinusoidal stimulator for a lithium ion battery; - to control the EVAL-L9963E-MCU board manufactured by STMicroelectronics through an SPI channel to manage the EIS acquisition. The source files could be used to better understand the stimulation/acquisition routine used in the linked paper. 2) In the file "MATLAB main code.txt" there is the MATLAB code used to communicate with the Pynq through a serial interface to download the measurement data acquired by the system. EIS DATA: In this folder you can find some MATLAB data file with the measurements obtained in every test performed in the paper: 1) EIS vs SOC - In this folder you can find some MATLAB data file with the EIS made at 6 different State of Charge (25%, 35%, 45%, 55%, 65%,75%) on a Lithium Cobalt Oxide (LiCoO2) 18650 2600mAh battery manufactured by Alcapower, part code LIR18650HFT. The sinusoidal stimulus signal is generated with a commercial battery charger manufactured by Microchip, part code MCP1630RD-LIC2. It is controlled to generate 100mA peak amplitude sinusoidal stimulus signals in a frequency range from 0.1Hz to 325Hz, with a DC offset of +100mA. The tests are made at an ambient temperature of 24°C+-2°C. 2) Reference RC load test - This folder contains the EIS measurements made on a reference RC load of a 5 Ohm resistor in parallel with a 22uF capacitor used to calibrate the EVAL-L9963E-MCU board. 3) Lithium battery EIS compensation - This folder contains the EIS measurements made with 100mA peak amplitude sinusoidal stimulus signal and zero DC offset, in a frequency range from 0.162Hz to 500Hz, on a Lithium Cobalt Oxide (LiCoO2) 18650 2600mAh battery manufactured by Alcapower, part code LIR18650HFT. The stimulus signal is generated by the Biologc SP200 impedance spectrum analyzer at an ambient temperature of 24°C+-2°C. 4) Reproducibility test - In this folder you can find some MATLAB data file with 90 impedance measurements made with 100mA peak amplitude and zero DC offset sinusoidal stimulus signal at four specific frequencies (1Hz, 10Hz, 100Hz, 500Hz), on a Lithium Cobalt Oxide (LiCoO2) 18650 2600mAh battery manufactured by Alcapower, part code LIR18650HFT. The measurements are made with EVAL-L9963E-MCU battery monitor and the stimulation and reference measurement are performed by an impedance spectrum analyser Biologic SP200."补充数据"文件夹包含了用于管理电化学阻抗谱（Electrochemical Impedance Spectroscopy，EIS）采集的代码，以及论文"A low-cost approach to on-board electrochemical impedance spectroscopy for a lithium-ion battery"测试环节所获取的EIS数据。 CODES: 1) "Pynq C代码"文件夹包含了运行于Pynq Z2微控制器上的C代码，附带用于实现两项核心功能的库文件： - 控制定制化现场可编程门阵列（Field-Programmable Gate Array，FPGA）模块，生成脉冲宽度调制（Pulse Width Modulation，PWM）型正弦激励信号，将其作为参考信号注入直流/直流（DC/DC）变换器的电流控制环路中，以此作为锂离子电池的正弦激励源； - 通过串行外设接口（Serial Peripheral Interface，SPI）通道控制STMicroelectronics生产的EVAL-L9963E-MCU开发板，实现EIS采集功能。 上述源文件可用于辅助理解关联论文中所采用的激励与采集流程。 2) "MATLAB main code.txt"文件中包含了通过串行接口与Pynq进行通信的MATLAB代码，用于下载系统采集的测量数据。 EIS DATA: 本文件夹内包含了论文中各项测试所得测量数据对应的若干MATLAB数据文件，具体分类如下： 1) 不同荷电状态下的EIS测试：本文件夹内包含了对Alcapower公司生产、型号为LIR18650HFT的钴酸锂（LiCoO₂）18650型2600mAh锂离子电池，在6种不同荷电状态（State of Charge，SOC，分别为25%、35%、45%、55%、65%、75%）下开展的EIS测试对应的若干MATLAB数据文件。 本次测试采用Microchip公司生产、型号为MCP1630RD-LIC2的商用电池充电器生成正弦激励信号，该信号峰值幅值为100mA，频率范围覆盖0.1Hz至325Hz，直流偏置为+100mA。测试环境温度为24℃±2℃。 2) 参考RC负载测试：本文件夹包含了针对参考RC负载的EIS测量数据，该负载由5Ω电阻与22μF电容并联组成，用于校准EVAL-L9963E-MCU开发板。 3) 锂离子电池EIS补偿测试：本文件夹包含了对Alcapower公司生产、型号为LIR18650HFT的钴酸锂（LiCoO₂）18650型2600mAh锂离子电池开展的EIS测量数据。本次测试采用峰值幅值为100mA、无直流偏置的正弦激励信号，频率范围覆盖0.162Hz至500Hz，测试环境温度为24℃±2℃，激励信号由Biologic SP200阻抗谱分析仪生成。 4) 可重复性测试：本文件夹内包含了90组阻抗测量数据对应的若干MATLAB数据文件，测试对象为Alcapower公司生产、型号为LIR18650HFT的钴酸锂（LiCoO₂）18650型2600mAh锂离子电池，测试参数为：采用峰值幅值100mA、无直流偏置的正弦激励信号，在4个特定频率（1Hz、10Hz、100Hz、500Hz）下开展测量。本次测试使用EVAL-L9963E-MCU电池监测板，激励与参考测量由Biologic SP200阻抗谱分析仪完成。