粉末电阻测试概述Overview of Powder Testing

材料电阻直接影响着全电池功率表现。通过测量分析粉末、极片电阻等特性，在快速预测电池性能方面具有重要意义。

   Resistivity  of material directly affects the power performance of full battery.  It is very important to predict the battery performance quickly by measuring and analyzing the characteristics of powder and electrode  resistivity .

   粉末导电材料的电阻率与材料本体电阻特性、粒度直接相关外，还与粉体堆积松紧度等直接关联。The resistivity of powder is not only directly related to the resistance characteristics and particle size of conductive material itself, but also directly related to the tightness of powder accumulation.

当前测量瓶颈Current situation and difficulties

粉末电阻的测试有多种方法，其中四探针是常用的方法之一。不过，四探针法仍存在如下问题亟需解决，以便方便高效地进行粉体电阻及压实密度的测试。Four probes is one of the commonly used methods for powder resistivity. However, the following problems need to be solved in order to facilitate and efficiently test powder resistance and press density.  

非原位（需预压片，再转移至设备上测试），测试过程繁杂，影响因素众多；Ex-situ test(requires prepressing, then transferring it to the equipment for testing). The testing process is complicated and there are many influencing factors.  

没有粉末电阻与压实密度一体设备；No powder resistivity and press density integrated equipment;  

无法实现不同压力下粉末电阻与压实密度同步测试； The synchronous test of powder resistivity and press density under different pressures cannot be realized;

无法实现大压力下粉末电阻与压实密度测试 ；The test of powder resistivity and press density under high pressures cannot be realized.

测试原理介绍Principle

测量模式介绍Test Mode

测试系统实现以下功能 (类似电池充放电，CC+CV模式，Step Charge 模式)；

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

不同加载压力速率到目标压力，目标压力保持一定时间， 直到电阻变化率小于0.01mΩ/s，完成测试；

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

系统参数Specifications

产品特色与优势Features and Advantages

这是一款等静压施压技术粉末特性测试的设备The first one introduce isostatic pressing technology for powder properties  test

电池与材料力推产品/Recommended by leading enterprises;

设备兼具四探针和两探针法超高压力粉末电阻/密度测试设备/Integrated two-probe, four-probe and high pressure for powder resistivity/density test；

新增预振实、脱模等工序保证测量更准确/

压力、电阻、温度、湿度、厚度等关键参数一站式采集与记录/pressure, resistance, temperature, humidity and thickness are recorded in one station

中英文操作界面/ Bilingual operation interface;

单点模式与线性模式可选/Single point mode and linear mode are optional;

MES连接通讯(定制)/ MES connection communication

测量关联预测与数据库管理模式/ Data prediction and Database management mode;

可靠性分析Reliability Analysis

测试系统采用的是可控压力加压的测试来保证接触一致性，从而确保了测量的可靠性及稳定性，设备测试结果可靠，并且能达到量具R&R的标准要求。Test system adopt the controllable pressurize test to guarantee the contact uniformity, reliability and stability of test.

R&R可区分的类别数为9.35；The number of distinguishable R & R categories is 9.35;

方差分量贡献率及研究变异值大小同样显示系统的可靠性良好；%SV and 6*SD also display the better system reliability;

应用领域与方向Application Fields

石墨混合压实密度分析Mixed Graphite Density Analyse

不同LFP材料测试分析Different LFP Material Analysis

为了研究更高压施压状态下粉体特性，以下为240MPa下三款LFP粉体的电导性及压实密度特性参数； To research powder characteristics under more higher pressure loading status, the below are resistivity and press density parameters of LFP powder under 240MPa;

三款材料中高能量型、能量型及倍率型的电阻率依次降低；The resistivity characteristics of three types materials match with the particle size design.

不同包覆改性LCO分析Doping LCO Analysis

钠电池正极电阻分析 Na-ion Cell Cathode Materials Analyse

针对钠离子电池正极材料的材料导电性进行测试分析，以下为一款聚阴离子正极粉体（NX系列）混合两种不同导电添加剂的电导性评估. The below is the resistivity of polyanionic-based cathode materials (NX series) mixed two conductive additives:

NX+1.3%导电剂B的整体电导性比NX+1%导电剂A的效果好很多；The whole resistivity of NX+1.3%B more better than NX+1% A;

三元材料电阻率评估NCM Resistivity Analysis

针对不同三元材料的电导性测试应用，粉末电阻测试系统能有效地区分不同材料电阻率；Test system able to measure different type NCM material resistivity;

另外，可以看出粉末电阻率与极片电阻呈相同变化趋势。Additionally, we can see that resistivity and electrode resistance shows the same trend.

石墨粉料生产稳定性评估Stability of Graphite production

为了提高电池的一致性与可靠性，传统克容量、颗粒度、BET等检测已经不足以保证材料的一致性。所以，对于评价材料一致性非常有用的粉末电阻率就变得越来越重要。In order to improve the consistency and reliability of the battery, the traditional specific capacity, particle size, BET and other tests are not enough to ensure the consistency of the material. Therefore, powder resistivity test becomes more and more important.

右图展现了不同生产批次石墨粉料的电阻数据，用于材料生产稳定性监控。 The picture show the resistivity data of different graphite batches, which is used to monitor the stability of material production.

粉末、极片与电芯电阻关联分析Correlation analysis of powder, electrode and Cell