Interfacial energy level alignment and energy level diagrams for all-solid Li-ion cells: Impact of Li-ion transfer and double layer formation

Experimental Studies on Work Functions of Li+ Ions and Electrons in the Battery Electrode Material LiCoO2: A Thermodynamic Cycle Combining Ionic and Electronic Structure

“…More recently, the origin of the voltage in LIB cells has been discussed by Jaegermann and co‐workers based on in situ measurements of surface potentials of TiS 2 , demonstrating that indeed the main contribution results from the electronic chemical potential difference but that also the ionic chemical potential difference could be significant . Such an appraisal is also supported by interface analysis which allowed to establish a full electronic structure diagram of a thin film cell …”

“…One approach is in fact based on a comparison of electronic work function difference to the measured open circuit voltage. For the (limited number of) systems where data are available it can be concluded that the difference in Li + ion chemical potentials is not large, i.e., that it is responsible only for a minor part of the cell voltage . Another approach to gain information on Li‐ion chemical potential differences between a Li + ion electrode‐ and a Li + ion electrolyte materials, is to measure the change in (electronic) work function (or related quantities such as band bending) upon forming a contact of the electrode with the electrolyte phase.…”

Reaction and Space Charge Layer Formation at the LiCoO2–LiPON Interface: Insights on Defect Formation and Ion Energy Level Alignment by a Combined Surface Science–Simulation Approach

“…The LiCoO 2 –LiPON interface is of interest for its relevance in thin film batteries and has been subject to investigation before by us and others . Previously, we studied the interface formation during the deposition of LiPON and reported the presence of a gradient layer in the LiPON as well as the electronic structure in the pristine state. − Wang et al have investigated the formation of interlayers by in situ TEM-analysis of a thin film cell, reporting a more extensive interface region in the LiCoO 2 and profound reactivity upon charging . Further, we investigate in this contribution the formation and evolution of LiCoO 2 –LiPON interfaces upon annealing in order to identify interlayer compounds related to the deposition process and to study the reactions and interlayer formation at the LiCoO 2 –LiPON interface.…”

First-Principles Prediction of Potentials and Space-Charge Layers in All-Solid-State Batteries

“…Solid-state electronic heterojunctions at solid-electrolyte/electrode interfaces play a critical role in determining ionic transport, and therefore performance, in these devices. Among various interfacial phenomena such as phase change [9], ionic distribution [2,10], and electrostatic potential drop [11][12][13], the formation of a "space-charge layer" at the electrode/solid-electrolyte interface is often cited as a barrier for lithium ion transport [14,15]. The driving force behind space-chargelayer formation is the chemical potential difference between contacting materials, which can result in depletion or enrichment of charged defects near the interface [16].…”