膨脹力測試概述About Pressure Analysis

?電芯實際使用時是束縛在模組內(nèi)，充放電過程中厚度的變化引起膨脹力會直接影響電芯、模組及電池包的電性能、安全及可靠性等表現(xiàn)。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.?

? ? ?為了研究清楚上述變化與關(guān)聯(lián)，對于電芯在實際工作時結(jié)構(gòu)與狀態(tài)的模擬與仿真（即電芯原位膨脹厚度、原位膨脹壓力特征參數(shù)）非常重要，其具體方式如下圖。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.

膨脹力測試概述About Pressure Analysis

材料不可逆損耗與劣化引起的極片/電芯逐漸變厚、析鋰等(如下圖)。對于膨脹及析鋰評價的傳統(tǒng)方法非原位、破壞性、成本高、效率低而且偏差大，已不能滿足當(dāng)前研究開發(fā)需求. 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, large deviation.

實現(xiàn)扣電、單層疊片、軟包與方殼電芯等原位膨脹力與厚度測量；Realize in-situ pressure and thickness test for Coin, single stack, pouch and prismatic cell;

為電芯材料開發(fā)、結(jié)構(gòu)設(shè)計、工藝優(yōu)化及相關(guān)機(jī)理研究提供支撐；Provide help for materials development, structural design, process optimization and related mechanism research;?

為模組、電池包設(shè)計提供可靠的結(jié)構(gòu)參數(shù)。 Provide reliable mechanical parameters for module, pack design.

解決方案與產(chǎn)品 Solution and Product

應(yīng)用領(lǐng)域與方向Application Fields

鋰電池、超級電容器等二次電池相關(guān)領(lǐng)域的生產(chǎn)制造企業(yè)、大學(xué)及科研院所科研過程；

Manufacturing enterprises, universities and scientific research institutes of lithium battery, supercapacitor and other secondary battery related fields;

普通原位膨脹力測試Ordinary in-situ Swelling pressure Analysis(ISPOA)

普通膨脹力測試方案

一體化恒間距膨脹力：New AIO Solution

針對電芯循環(huán)原位單純膨脹力測量場景，開發(fā)了全新一體化傳感器方案A new integrated sensor scheme is developed for ISPOA.?

更簡單的裝配結(jié)構(gòu)，易于安裝使用；Simpler structure, easy to install and use;

更小的體積占用率，提高環(huán)境箱體積利用率; Smaller volume occupancy rate, improve the volume utilization rate of oven;

更少的結(jié)構(gòu)件，更低的購置與使用成本; Fewer structural parts, lower acquisition and use costs

普通墊片恒間隙膨脹力

? For in-situ swelling pressure testing, we optimized and developed high-precision adjustable constant gap module based on the traditional three-splint scheme.針對電芯循環(huán)原位單純膨脹力測量場景，川源科技基于傳統(tǒng)的三夾板方案優(yōu)化開發(fā)高精度可調(diào)恒間隙測試模塊。

High-precision mould with overall parallelism up to 5μm (the same accuracy during test) 高精度模架設(shè)計，整體平面平行度最高達(dá)5μm（測試過程中同等精度保證）;

Manual adjustable constant gap, to achieve different thickness requirements;人工可調(diào)恒間隙設(shè)計，實現(xiàn)不同電芯厚度需求

Cicada sensor developed a new-generation? sensor for battery, reliable and durable; 知了傳感技術(shù)開發(fā)的新一代電池專用傳感器，可靠耐用；

數(shù)據(jù)采集器Data Collector

夾具預(yù)緊力保證系統(tǒng)Pretightening Force Guarantee System

背景與困難

當(dāng)前測試人員使用夾具對電池大面進(jìn)行扭力緊錮時使用扭力扳手?jǐn)Q到大概的數(shù)值，由于器具的精度和不同人員的操作習(xí)慣問題，會導(dǎo)致最終的結(jié)果差異較大，主要表現(xiàn)如下幾種情況：

適用不帶扭力顯示的扳手，不通螺絲扭力一致性；

壓板歪曲不平行；

扭力不夠?qū)е码姵卦谝苿拥倪^程中偏離中間；

扭曲后壓力釋放，并且無法測量評估。

對于準(zhǔn)確控制夾具預(yù)緊力的需求十分必要。

解決方案Solution

自動預(yù)緊力系統(tǒng)

原位膨脹壓力分布測試? In-situ Swelling Pressure Distribution Analysis

原位壓力分布測試 In-situ Swelling Pressure Distribution

原位壓力分布測試 In-situ Swelling Pressure Distribution

薄膜傳感器原理

薄膜感測片由上下兩層柔性可彎折的薄膜材料組成，上層為壓感功能薄膜，下層為電極薄膜感測片受壓時，上下兩層薄膜發(fā)生接觸，其接觸面積、接觸形變會隨著壓力大小變化而變化，從而使電極端產(chǎn)生隨壓力變化而產(chǎn)生的電阻抗信號量的變化。

感測片上每一個壓力點的原始壓力特性呈現(xiàn)為與受壓壓力線性變化的一條壓力曲線。感測片的出廠測試、標(biāo)定過程中，會記錄每一個點的原始壓力曲線，形成每一感測片專有的MAP標(biāo)定文件。

原位膨脹壓力分布測試方案

原位壓力分布測試 In-situ Swelling Pressure Distribution

消 費 類 電 池 化 成 壓 合 與 壓 敏 紙 對 比，可以看出電芯循環(huán)過程中出現(xiàn)受力不均勻情況。同時，化成設(shè)備的夾具之間夾板力出現(xiàn)不均勻； It can be seen that the pressure is not uniform in the process. At the same time, the splint pressure between the jigs of the formation equipment is uneven.

多通道?原位膨脹壓力/厚度測試? ? Multichannel In-situ Swelling Analysis System

適用于扣電、單層疊片、圓柱、軟包與方殼等各種類型電芯評估

For various types of cell such as coin cell, single layer stack cell, pouch and prismatic.?

當(dāng)前測量瓶頸Current situation and difficulties

多通道原位膨脹Creativeness Solution

測試系統(tǒng)通過集約化集成高精度模架、位移、電壓、電流、壓力、溫濕度等核心零部件與傳感器，實現(xiàn)不同工況下的原位厚度、膨脹力檢測。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 cell.?

系統(tǒng)測試模式介紹Working Mode

測試系統(tǒng)實現(xiàn)以下功能 (類似電池充放電，CC+CV模式，Step Charge 模式)；

Test system realize the following function（similar to cell test, CC+CV mode，Step Charge mode）：

不同加載壓力速率到目標(biāo)壓力，目標(biāo)壓力保持一定時間， 直到電阻變化率小于0.01mΩ/s，完成測試；

For example ：0.1t/s? Constant? Force rate(CFR) to 0.3t, Constant Force(CF) to 0.01mΩ/s, Frequency 0.2S。

測試系統(tǒng)概覽Product Overview

測試系統(tǒng)參數(shù)Product Specifications

產(chǎn)品特色與優(yōu)勢Features and Advantages

傳統(tǒng)單通道與多通道區(qū)別

可靠性分析：Reliability Analysis

動態(tài)恒壓模式：測試系統(tǒng)實際保壓壓力值在目標(biāo)壓力±5N的范圍內(nèi)波動；

Dynamic Constant Pressure Mode: The actual pressure holding value of the test system fluctuates within the range of the target pressure ±5N.?

應(yīng)用領(lǐng)域與方向Application Fields

鋰電池、超級電容器等二次電池相關(guān)領(lǐng)域的生產(chǎn)制造企業(yè)、大學(xué)及科研院所科研過程；

Manufacturing enterprises, universities and scientific research institutes of lithium battery, supercapacitor and other secondary battery related fields;

不同Binder開發(fā)評估In-situ Swelling Analysis@Diff. Binder R&D

對于不同樣陽極Binder材料電芯膨脹水平評估，三種材料表現(xiàn)出明顯的差異(PI-2<PAA<SBR)，此方法可以為binder等材料開發(fā)提供有力技術(shù)支持；

Accurate measurement of the swelling of cell based different binder(PI-2<PAA<SBR), It provides strong technical support binder development;

極片熱輥壓工藝膨脹評估Swelling Analysis@Electrode Hot Press R&D?

在電芯膨脹改善工藝開發(fā)中，通過原位膨脹測試能明顯看出經(jīng)過熱輥極片組別的電芯整體膨脹水平降低并且不可逆膨脹也減小。In the process of cell swelling improvement, it can be seen that the overall swelling level and irreversible THK of the cell based on hot press electrode decrease.?

不同倍率原位膨脹分析In-situ Swelling Analysis@Different Rate

精準(zhǔn)測量不同倍率電芯變化(倍率越小電芯膨脹厚度越大),為評估電芯原位膨脹性能提供有力技術(shù)支持；Accurate measurement of the swelling of cell based different Rate(The smaller charge rate of cell show thicker swelling), It provides strong technical support Cell design and development.

恒壓力不可逆膨脹分析Irreversible Swelling Analysis@Constant Pressure?

在恒壓力測試模式下，循環(huán)過程中電芯膨脹力保持動態(tài)不變；In constant pressure mode, the cell swelling pressure unchanged during charge-discharge.

每個循環(huán)電芯不可逆膨脹厚度增加幅度為1-2μm，電芯的前三個循環(huán)的不可逆膨脹厚度分別為0.9μm, 1.0μm, 1.3μm; The Irreversible swelling thickness of cell increase 1-2μm, and the irreversible swelling thickness is 0.9μm, 1.0μm, 1.3μm, respectively.?

恒壓力原位膨脹分析In-situ Swelling Analysis@Diff. Constant Pressure?

在恒壓力測試模式下，循環(huán)過程中電芯膨脹力保持動態(tài)不變；In constant pressure mode, the cell swelling pressure unchanged during charge-discharge.

隨著加載壓力增加，電芯膨脹絕對厚度相應(yīng)降低；The absolute thickness of cell decreases with the increase of loading pressure.

隨著充電電流的下降(CC+CV階段)，電芯膨脹厚度增加速率逐步減小；With the decrease of charging current (CC+CV stage), the increase rate of cell expansion thickness gradually decreases.

扣電原位膨脹評價In-situ Coin Cell Swelling Analysis: NCM vs. Li

傳統(tǒng)扣電由于其整體高度固定，導(dǎo)致無法控制極片界面、無法獲取充放電過程中厚度信息等。Coin cell is one of the most important method to evaluate materials. Due to the fixed space of coin cell, the interface can’t be controlled and the thickness change is unknown during charging-discharging.

在充電過程中，隨著NCM脫鋰，Li金屬嵌鋰，總體厚度膨脹增長；

During charge, NCM cathode delithiation, Li anode lithiation, the total thickness increase;

在放電過程中，鋰金屬脫鋰后厚度降低，但由于整體不可逆反應(yīng)而厚度增長；

During discharge, Li anode delithiation, the total THK decrease, the irreversible swelling THK increase:?

圓柱電芯原位膨脹分析

原位膨脹測試系統(tǒng)同樣能適用于圓柱電芯的評價，在49N的恒定壓力下，26105型圓柱電芯的相對直徑最大變化在42.3μm左右，整體直徑隨著循環(huán)進(jìn)行逐漸增大；Under a constant pressure of 49N, the maximum diameter of the 26105cylindrical cell is 42.3μm, and the overall diameter gradually increases as the cycle progresses;

此設(shè)計的電芯膨脹率約為0.166%@100%SOC； The swelling rate of the cell is approximately 0.166% @ 100% SOC;

雙通道測試系統(tǒng)恒壓力模式

雙通道系統(tǒng)保證電芯樣品在完全一樣的壓力下進(jìn)行測著，隨著電芯充電的進(jìn)行，電芯膨脹絕對厚度及相對厚度被同步檢測；兩個同樣設(shè)計的電芯表現(xiàn)出來的膨脹水平一致（厚度變化一致），但是2號電芯的極化相對更大；

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;

電芯無損析鋰分析Nondestructive ALP Analysis

析鋰為最嚴(yán)重的電芯安全風(fēng)險之一，所以對于電芯析鋰的分析與預(yù)測非常重要；通過原位膨脹檢測可以對電芯的析鋰情況進(jìn)行預(yù)測分析。

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.

電芯膨脹力及厚度預(yù)測Swelling Pressure and THK Forecast?

基于原位膨脹力測試系統(tǒng)，通過電芯循環(huán)過程的膨脹數(shù)據(jù)，進(jìn)行電芯不同工況下膨脹預(yù)測與分析；

Based on in-situ swelling pressure test system, we can predict the level of cell swelling pressure and thickness;