Li-ion Batteries

Finden works directly with clients on short commissioned projects, but is also involved in long term research projects with clients and partners from across the world. Examples are given below including a case study.

Further case studies include:


Spatially Resolving Lithiation in Si-graphite Composite Electrodes via in situ High-resolution XRD-CT

Optimizing the chemical and morphological parameters of lithium-ion (Li-ion) electrodes is extremely challenging, due in part to the absence of techniques to construct spatial and temporal descriptions of chemical and morphological heterogeneities. We present the first demonstration of combined high-speed X-ray diffraction (XRD) and XRD computed tomography (XRD-CT) to probe, in 3D, crystallographic heterogeneities within Li-ion electrodes with a spatial resolution of 1 μm.

 

Lattice parameters from XRD-CT reconstructions of the LixMn2O4 electrode during lithiation
Solid-state chemistry in secondary LiMn2O4 (LMO) particles during lithiation and its impact on the performance of the electrode

The performance of lithium ion electrodes is hindered by unfavorable chemical heterogeneities that pre-exist or develop during operation. Time-resolved spatial descriptions are needed to understand the link between such heterogeneities and a cell’s performance. Here, operando high-resolution X-ray diffraction-computed tomography is used to spatially and temporally quantify crystallographic heterogeneities within and between particles throughout both fresh and degraded LixMn2O4electrodes.

 

 

 

Multi Length Scale Chemical X-ray imaging fig

Characterisation of NMC Electodes used in Li-ion Batteries

Environmental considerations and a further electrification of the global automotive fleet and energy grid systems are driving the need for robust electrochemical energy storage devices. While lithium-ion (Li-ion) batteries have emerged over the last few decades as the prime choice for powering portable consumer electronics, they are also being employed for a wider range of applications due to their high energy densities and specific capacities. Since its discovery, lithium cobalt oxide (LCO) has been one of the most commonly used materials in Li-ion electrochemical storage devices and has been employed in numerous applications. High cobalt costs and its inherent toxicity have driven the exploration of other chemistries with reduced Co content, such as lithium nickel manganese cobalt oxide (NMC), where the slightly lower capacity is compensated by excellent power and low self-heating during cycling. However, to meet the demands of modern applications, improvements are required to increase the cycle life, capacity and safety of these materials. We have applied the XRD-CT technique to investigate NMC electrodes cycled at different voltages using a 1 μm X-ray beam.