On the electrochemistry of an anode stack for all-solid-state 3D-integrated batteries

Lithium barrier materials for on-chip Si-based microbatteries

“…We found that during charging the Li uptake of Ta is ca. 0.09 Li, this value is in good agreement with literature data [14]. During discharging the value reduces to 0.02 Li per Ta.…”

“…The corresponding discharge curve of the cell equipped with TiN reveals a capacity being lower than 1 × 10 −3 µAh cm −2 ; because of the restrictions in sensitivity of the test equipment used; the limit was 75 nA, thus, very low currents cannot be determined with high precision. The capacity of a TiN layer is supposed to depend linearly on the layer thickness, for TiN values of 0.02 Li per formula were calculated [14]. Here, considering the discharge capacity experimentally a value of 0.002 Li atoms per TiN formula unit was found which is significantly lower than the calculated result (see Table 5).…”

“…The overall ion dynamics of a microbattery with Li + as charge carrier, meaning both the desired and undesired transport phenomena as well as the underlying reaction kinetics, strongly depends on the materials chosen to construct the battery and to encapsulate it. As it has been shown by Notten et al [14], TiN and TaN turned out to be promising blocking materials. Cyclic voltammetry has revealed that nitrides seem to be indeed electrochemically stable against Li metal.…”

All‐Solid‐State Lithium‐Ion Microbatteries: A Review of Various Three‐Dimensional Concepts

“…[ 149 ] Films of these materials can be deposited with several deposition techniques. Silicon fi lms can, for example, be deposited using low pressure chemical vapor deposition [ 150 ] and evaporation. [ 151 , 152 ] The group IVb elements have a very high lithium uptake: the lithium content can theoretically be increased up to approximately 4008 mAh ⋅ g − 1 for Li 21 Si 5 , 1565 mAh ⋅ g − 1 for Li 21 + 3/16 Ge 5 , 963 mAh ⋅ g − 1 for Li 21 + 5/16 Sn 5 and 556 mAh ⋅ g − 1 for Li21 + 1/4Pb 5 .…”

“…The etched 3D structure typically consists of trenches, [ 178 ] but various other geometries can also be made, like pores or pillars. [ 150 ] Commonly used dimensions for etched trench structures vary from 1 μ m to 30 μ m in width, and 10-100 μ m in depth. The surface area enhancement can be calculated for a trench structure using…”