一种多通道电芯原位膨胀力测试新方法
电芯实际使用时是束缚在模组内，充放电过程中厚度的变化引起膨胀力会直接影响电芯、模组及电池包的电性能、安全及可靠性等表现。
During charge and discharge, the cell’s thickness change lead to the pressure variation, directly influence the performance of electrochemical properties, safety and reliability of cell, module and battery.为了研究清楚上述变化与关联，对于电芯在实际工作时结构与状态的模拟与仿真（即电芯原位膨胀厚度、原位膨胀压力特征参数）非常重要，其具体方式如下图。In order to study the change and correlation clearly, the modeling and simulation for the actual work structure and status of batteries (in-situ thickness, in-situ pressure characteristic parameter) are very important. as is shown in the following diagram.Diagram 1 Pack-Module-Cell材料不可逆损耗与劣化引起的极片/电芯逐渐变厚、析锂等(如下图2)。对于膨胀及析锂评价的现有传统方法非原位、破坏性、成本高、效率低而且无法实现多个样品同步平行测试，已不能满足当前研究开发需求，如对比图表2.Irreversible loss and degradation lead to electrode /Cell gradually thickness increase, ALP, etc. Ex-situ and destructive traditional methods can't meet current requirement due to its high cost, low efficiency, only one sample can be tested in one experiment.•实现多通道扣电、单层叠片、软包与方壳电芯等原位膨胀力与厚度测量；Realize Multichannel in-situ pressure and thickness test for Coin, single stack, pouch and prismatic cell;•为电芯材料开发、结构设计、工艺优化及相关机理研究提供支撑；Provide help for materials development, structural design, process optimization and related mechanism research;•为模组、电池包设计提供可靠的结构参数。
Provide reliable mechanical parameters for module, pack design.
Diagram 2. Comparison table of advantages of the new method1.多通道原位膨胀力测试系统简介Introduction
多通道原位膨胀力测试系统通过集约化集成高精度模架、位移、电压、电流、压力、温湿度等核心零部件与传感器，实现不同工况下多电芯同步原位厚度、膨胀力检测。Through intensive integration of high-precision die frame, displacement, voltage, current, pressure, temperature and humidity and other core components and sensors, the test system can accurately test In-situ thickness and swelling pressure of multiple cells at one time.•多通道同步电芯原位膨胀力测试；Multichannel In-situ Swelling Analysis System•完全一体化，测试、采集、处理一站式解决；AIO, one-stop solution;•可适配用于扣电、单层叠片、软包与方壳铝壳等各类电芯For coin, single stack, pouch and prismatic cell;•高精度厚度测量分辨率0.1µm，精度±1µm；high precision thickness measurement, resolution is 0.1μm and accuracy is ±1μm;•高精度持续动态压力保证，最高波动±10N；high precision continuous dynamic pressure guarantee, maximum accuracy is ±10N;•全方位电流、电压、压力、厚度、温湿度等数据同步监测采集；synchronous monitoring and collection of Electrochemical parameters, pressure, thickness, temperature, humidity, and so on.•不同测试温度（-40℃~100℃）环境模拟；Environmental simulation at different test temperatures (- 40 ℃~100 ℃);Diagram 3. Multichannel In-situ Swelling Analysis System2.应用示例Application
在双通道原位膨胀测试模式下，保证了电芯样品在完全一样的压力控制水平下进行测试；随着电芯充电的进行，电芯膨胀绝对厚度及相对厚度被同步检测；两个同样设计的电芯表现出来的膨胀水平一致（厚度变化一致），但是2号电芯的极化相对更大；In the dual-channel in-situ expansion test mode, the cell sample is guaranteed to be tested at exactly the same pressure; With the charging of the cell, the absolute thickness and relative thickness of the cell are detected synchronously; Two cells based on the same design exhibit the same level of swelling (thickness changes consistently), but the polarization of cell 2 is relatively larger;在恒压力测试模式下，循环过程中电芯膨胀力保持动态不变；随着加载压力增加，电芯膨胀绝对厚度相应降低；随着充电电流的下降(CC+CV阶段)，电芯膨胀厚度增加速率逐步减小；In constant pressure mode, the cell swelling pressure unchanged during charge-discharge. The absolute thickness of cell decreases with the increase of loading pressure. With the decrease of charging current (CC+CV stage), the increase rate of cell expansion thickness gradually decreases.析锂为最严重的电芯安全风险之一，所以对于电芯析锂的分析与预测非常重要；通过原位膨胀检测可以对电芯的析锂情况进行预测分析。ALP(Anode Lithium Plating) is the most safety issue, so the analysis and prediction of ALP is very important. Based on in-situ swelling pressure testing system,) ALP can be predicted.3.总结Summary
本文采用多通道原位膨胀测试系统CSA1150对电池进行原位膨胀测试，解决现有测量方法一次只能测试一个平行样品的问题，并完全保证了电芯测试的压力控制的一致性，有助于更准确更快速地评估材料改性及工艺配方开发。In this paper, the multi-channel in-situ swelling test system (CSA1150) is used to test the swelling of cell, which solves the problem that the existing measurement method can only one parallel sample be tested at a time, and fully ensures the consistency of the pressure control of the test, which is helpful to evaluate the material modification and the process formulation development more accurately and quickly.原位膨胀测试系统参数 
