发表机构
University of Oxford; The Faraday Institution; Battery Dynamics（牛津大学; 法拉第研究所; 电池动力学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究锂离子电池表征，采用多正弦波电化学阻抗谱，通过商用恒电位仪在宽频范围测量，与单正弦波EIS比较，讨论优势及验证条件，还在不同工况测宽带阻抗，为电池多方面性能提供新见解。
AI 中文摘要
电化学阻抗谱（EIS）是用于非侵入式电池表征的重要工具，能在较宽时间尺度上提供物理过程的简洁数据表示。通常采用顺序注入不同频率正弦波（单正弦波）的方式，而多正弦波激励（正弦波之和）有利于减少实验时间并能在工作条件下（如充电、放电、弛豫和温度变化期间）测量阻抗。本文展示了使用商用恒电位仪在宽频率范围（20 mHz至1 kHz）对锂离子电池进行的高保真多正弦波EIS测量，并与单正弦波EIS进行比较，讨论了两种技术的优势以及如何验证线性和平稳性条件。还测量了不同工作条件下（充电/放电、弛豫和温度变化期间）的宽带多正弦波阻抗，展示了该工具如何为电池动力学、材料特性、电荷转移过程和热性能提供新见解。
英文摘要
Electrochemical impedance spectroscopy (EIS) is a valuable tool for non-invasive battery characterisation, providing a compact representation of physical processes over a wide range of time scales. Commonly, sinusoids at different frequencies are injected sequentially (single-sines). Alternatively, a multisine excitation (a sum of sines) is advantageous for reducing experiment time and allowing impedance to be measured during operation. In this work, we demonstrate high-fidelity multisine EIS measurements on Li-ion cells over a wide frequency range (20 mHz to 1 kHz), taken with a commercial potentiostat modified to give access to the underlying current and voltage time-series data, and compare these to single-sine EIS. We show how this allows the conditions of linearity and stationarity to be verified directly, which is not possible with impedance data alone. We then measure broadband impedance during charging and discharging, temperature change, and relaxation. Because impedance is a linearisation of the response about an operating point, each of these conditions probes a state that classical EIS excludes by definition: kinetics linearised about a non-zero current, thermally activated reaction rates, and relaxing concentration gradients, respectively. Operando multisine EIS is therefore not simply a faster measurement approach, but one that resolves behaviour that steady-state EIS cannot.
