Poseidon Select Liquid Microscopy Cell
The Poseidon Select Liquid Electron Microscopy system is the most flexible liquid cell on the market. The system is configurable and expandable with Heating and Electrochemistry packages designed for a variety of research interests. Poseidon Select is the only liquid microscopy holder that is truly EDS compatible. It is the safest in situ liquid system on the market and has been fully evaluated and approved by electron microscope manufacturers. Poseidon Select offers the widest variety of liquid microscopy E-chips, including ultra-thin <150nm liquid layers for high-resolution imaging.
The Poseidon Select Liquid Microscopy Advantage
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The Poseidon Select Key Features
▶ Configurable and expandable design with Heating and Electrochemistry packages that can be added depending on your area of interest
▶ Patented design capable of obtaining the highest-quality EDS results available
▶ 3 electrodes (WE,CE, RE) integrated within the tip of the Poseidon Select holder
▶ 3-port (mixing) TEM holder with integrated electrodes and a touch-screen controlled syringe pump
▶ Ultra uniform Liquid Heating from RT to 100 °C closed-loop control
▶ Safe, easy-to-use method for replacing the interior tubing of a holder
▶ A wide variety of replaceable E-chips that control liquid thickness from <50 nanometers to >5 microns
The liquid heating package can also be added to any Poseidon Select 500 or 510 system.
In Situ Lithium Dendrite Deposition
A key challenge in the development of lithium-ion battery materials is combating the formation of lithium dendrites on the electrode surface after repeated charge/discharge cycles. As dendrites form over repeated cycles, so-called “dead” lithium no longer participates in ion transport. This leads to a reduction in battery capacity, while increasing the potential for the formation of a short circuit between the anode and the cathode.
Researchers used Protochips’ Poseidon Select system to observe the charge/discharge process of lithium-ion batteries in solution using scanning TEM (STEM). A series of real-time STEM images of the working electrode was acquired as the electrochemical potential of the cell was simultaneously cycled from 0 to -4 volts.
At the start of the first cycle, the surface of the platinum working electrode was pristine, and all the lithium was dissolved in the electrolyte solution. As the battery was charged, lithium was deposited on the surface of the working electrode; surface roughening was observed, as the lithium was not deposited in an even layer. Discharging of the battery during the first cycle led to a reduction in lithium on the electrode surface, but lithium dendrites remained on the surface of the electrode and did not redissolve in the electrolyte.
As the number of charge cycles increased, an increase in irreversibility of the electrochemical cell was observed, corresponding to the formation of lithium dendrites and “dead” lithium regions visible in the STEM images. Also visible in the CV curves were characteristic peaks at -2 and -2.5 volts, indicating alloying between the platinum electrode and the lithium in the electrolyte.
Using the Poseidon Select system, researchers successfully imaged the formation of lithium dendrites during battery charge/discharge cycles, while simultaneously collecting electrochemical data using STEM.