Battery Materials
Atomic force microscopy is particularly well suited as a tool for Lithium ion battery research to address the key challenges of improving battery capacity, power density, lifetime, and safety. Fundamentally, a battery is an electrochemical cell, and electrochemical AFM can serve to probe changes of the electrode surface directly, in situ and in operando, and even measure variations in local electrochemical activity. For example, AFM studies of high-capacity Li ion anodes can help understand the evolution and degradation of the solid-electrolyte interphase (SEI) layer, which limits power density and battery lifetime. At the cathode, correlated electrical and mechanical characterization can quantify component distribution, characterize conductivity variation, and pinpoint inactive metal oxide grains that limit capacity. Finally, AFM imaging of the separator membrane on a tensile stage can provide insight into the fracture mechanism operating when dendrite growth leads to catastrophic failure.
The ability to measure local electrochemical activity and surface conductivity in situ, in the presence of electrolyte is equally useful for the characterization of other energy storage and conversion approaches such as supercapacitors, fuel cells, and solar fuel.
关键功能
- In situ, in operando characterization during anode charging cycles with EC-AFM
- SEI层对高容量阳极的定量研究PeakForce QNM®
- 直接探测局部电化学活性PeakForce SECM®
- Multimodal cathode characterization withDataCube®模式
- Turnkey solutions forEC-AFM，secm和杂物盒集成
The Anode – In Situ, In Operando Imaging
锂离子电池的寿命主要取决于钝化SEI层的形成和演化。挑战在于电池循环过程中大电极的变化，这导致SEI层的实质性变形，尤其是对于高容量阳极。理想的实验将直接在Operando中直接探测脆弱的SEI层，这一壮举被认为是非常困难的。此处显示的一系列图像仅此而已，并且来自与布朗大学的谢尔顿集团一起进行的协作工作。这里使用Peakforce QNM观察到图案化的Si阳极，在集成的杂物盒中Dimension Icon®with electrochemical cell. For the first time, the formation of cracks in the SEI layer is observed directly, during lithiation. The mechanical degradation is being tracked during multiple charging cycles, which are shown not to repair the initial crack completely, contradicting prior speculation.
These experiments also open the door to estimating the fracture toughness, a key parameter for breakdown of the SEI layer (see our coauthored ACS Energy Letters article, “In Situ and Operando Investigations of Failure Mechanisms of the Solid Electrolyte Interphase on Silicon Electrodes”）。有关SEI层的进一步研究，请参见最近的《自然传播》文章“Lithium Anode Stable in Air for Low-Cost Fabrication of a Dendrite-Free Lithium Battery，”由诺贝尔奖获得者约翰·古德纳（John Goodenough）合着。
The Cathode – Multimodal Characterization
锂离子阴极是一种复杂而异质的混合物，其中包含金属氧化物颗粒，以将锂存储在放电状态下，周围环绕聚合物粘合剂材料，可容纳与碳黑色材料混合的体积变化，以维持高电导率，从而能够提供高功率密度。这里的图像系列显示了Datacube SSRM如何Dimension Icon XRhelps map out the component distribution and uncover drastic particle to particle variation. Here the modulus map available in DataCube mode clearly distinguishes the hard metal oxide particles from the surrounding soft binder, while a concurrently acquired conductivity map reveals the uneven distribution of carbon black. A particle near the top edge of the image is seen not to be covered by carbon black and a series of conductivity images extracted from the same data cube identifies this particle as dead, i.e., inactive over the entire range of operating voltages.
More Information
阅读我们的电池研究电子书，该电子书介绍了用于表征锂离子电池材料的主要分析技术，包括原子力显微镜（AFM）表征。必威手机客户端该电子书解释了这些技术及其各种模式如何工作，并详细介绍了它们用于分析电池材料以及它们可以生成的信息。必威手机客户端它还提出了案例研究，以说明实验室的工作科学家如何应用这些技术。
Recent Webinars
相关出版物
- Shen et al, “Lithium Anode Stable in Air for Low-Cost Fabrication of a Dendrite-Free Lithium Battery,”Nature Communications10, 900 (2019), DOI:10.1038/s41467-019-08767-0.
- Becker等人，“使用原位AFM确定的ALD涂层的lithiation循环稳定性”，ACS Appl. Mater. Interfaces2016，8，1，530-537。
- Chen et al, “Deformation and Fracture Behaviors of Microporous Polymer Separators for Lithium Ion Batteries”RSC Advances2014, 4, 1409.
- Hiesgen等人，“ AFM作为Li – S电池高容量阳极阴极的分析工具”贝尔斯坦纳米技术杂志2013年,611。
- Hiesgen et al, “Microscopic Analysis of Current and Mechanical Properties of Nafion® Studied by Atomic Force Microscopy”膜2012，2，783。
- Kumar et al, “Strain-Induced Lithium Losses in the Solid Electrolyte Interphase on Silicon Electrodes”ACS Appl Mat & Int2017，9，28406。
- Kumar et al, “In Situ and Operando Investigations of Failure Mechanisms of the Solid Electrolyte Interphase on Silicon Electrodes”,ACS Energy Letters2016，1，4，689-697。
- Lakowski et al, “Nanoscale Semiconductor/Catalyst Interfaces in Photoelectrochemistry”,Nature Materials，2019年;doi：10.1038/s41563-019-0488-Z。
- Nellist et al, “Potential-Sensing Electrochemical Atomic Force Microscopy for In Operando Analysis of Water-Splitting Catalysts and Interfaces”,Nature Energy2018, 3, 46.
