Empower your battery research with new solutions

by Umesh Tiwari, Wednesday, 16th March 2022

Despite the large-scale commercialization of batteries in electric vehicles and energy storage, battery technologies are still evolving at a disruptive pace to meet the ever-evolving consumer needs – high specific energy and power, faster charging times, greater safety, and lower cost.

It is mainly the Lithium-ion batteries that are present in portable electronic devices and in electric vehicles. But, while lithium (Li) still provides a large part of the currently available electrode materials, the availability of Li on Earth remains limited. Moreover, future technologies should also minimize the use of toxic materials and carbon-heavy processes to be identified as “Green” in real terms.

As a result, the development of low-cost electrode materials using alternative chemistry has been a topic of high interest in the scientific community. Solid-state electrolytes would enable the use of Li metal anodes, reducing the size, increasing the energy capacity, and improving the safety of current batteries. Alternative chemistries based on Na or Mg are being investigated to replace Li to drive the costs down. 

Electrode material characterization

For any new electrode material to be successful for battery application, its crystal structure and structural stability with charge-discharge cycling are the parameters of critical importance. Malvern Panalytical  X-Ray Diffraction (XRD) solutions are specially customized for battery research, offering both powder materials characterization for structural integrity and in-operando characterization to investigate their electro stability during charge-discharge cycling. 

Local structure and short-range order: pair distribution function analysis

In materials that lack long-range order, we can analyze the local structure and short-range order with pair distribution function (PDF) analysis. Our Empyrean XRD can be configured for PDF measurement using a hard radiation source (Mo, Ag) and high photon counting efficiency GaliPIX3D detector. An example: the investigation of the local order of Na in the pristine layered Na2/3[Mn1/2Fe1/2] O2 electrode using Ag radiation.

Figure 1. PDF measurement of the material electrode using Ag radiation (data taken from E. Talaie et al., Energy Environ. Sci., 2015,8, 2512-2523)

Phase changes during charge/discharge: in operando study

In operando XRD can help you track the changes in the lattice parameters or the crystal phase itself. Such changes, if not understood and controlled, may lead to particle cracking and eventually battery degradation.

Ion exchange in a lithium-ion battery
Figure 2. Schematic view of the ion exchange in a lithium-ion battery in a lithium-ion battery

We can measure the charging/discharging cycle of an LNMC commercial prismatic battery cell using Ag radiation, showing phase changes in the anode and cathode.

Figure 3. In operando measurement of a commercially available prismatic cell
Figure 4. Variation in the XRPD data during two full charge and discharge cycles. The peaks at about 8.5° and 17° 2theta belong to the LiNMC phase, (003) and (101) reflections respectively. The peak at about 12° 2theta is the (002) reflection of graphite.

For further reading download the Application Note ”High-quality in operando X-ray diffraction analysis of pouch bag lithium-ion batteries“.

New in operando XRD functionalities

With the research landscape constantly changing, the requirements change as well. And to stay ahead of the need within battery R&D, analytical instrumentation manufacturers like Malvern Panalytical must keep developing new solutions.  A battery may be perfect at 25°C but, actual operating conditions may be very far from that. To investigate battery stability under non-ambient conditions, we have introduced 2 new battery stages on our Empyrean XRD platform.

VTEC: This is an electrochemical cell with Be window at the top. In addition, there is heating/cooling option -15°C to 70°C. This stage can be used with conventional Cu radiation in reflection geometry.

VTEC electrochemical cell with in-situ heating and cooling mounted on Empyrean XRD
Pouch cell stage with in situ heating and cooling for in operando XRD

VTEC-Trans: This is a special stage to heat and cool pouch cells from -10°C to 70°C. Heating and cooling is controlled by a Peltier. Pouch cells up to 10×10 cm can be mounted on this stage. Mo/Ag radiation is preferred for transmission through thick pouch cells, though Cu radiation can be used for single-layer pouch cells with perforated current collectors.

Investigate your battery under non-ambient conditions

Whether you’re part of an independent research organization, work for a battery manufacturer, or work in the field of battery research at a university, these two new battery stages would be highly useful for your research. Join the upcoming launch webinar to discover what it means to have these in your lab.

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