Thin Film Model Systems: Thin Film NCM Cathodes as Model Systems to Assess the Influence of Coating Layers on the Electrochemical Performance of Lithium Ion Batteries (Adv. Mater. Interfaces 9/2021)

Correlation between Surface Reactions and Electrochemical Performance of Al2O3‐ and CeO2‐Coated NCM Thin Film Cathodes

“…The charge capacity in Figure 3 is normalized to the charge capacity of the second cycle as the capacities of the cells vary slightly for each thin film due to difficulties in determining exactly the masses and thicknesses of the films. [ 30 ] The non‐normalized values are presented in Figure S1, Supporting Information of the SI. After 20 cycles, the Al 2 O 3 ‐coated sample retains 82.6% of its charge capacity in the second cycle, while the uncoated and CeO 2 ‐coated samples retain 74.9% and 69.5%, respectively.…”

“…The model thin film cathodes were prepared via a sol‐gel approach using spin‐coating as described in ref. [30]. In brief, stoichiometric amounts of lithium nitrate (LiNO 3 ·H 2 O, 99.99%), nickel (II) nitrate hexahydrate (Ni(NO 3 ) 2 ·6 H 2 O, 99.999%), cobalt (II) nitrate hexahydrate (Co(NO 3 ) 2 ·6 H 2 O, 99.999%), manganese (II) nitrate tetrahydrate (Mn(NO 3 ) 2 ·4 H 2 O, 99.99%), and 150 mg polyvinylpyrrolidone (PVP, average molecular weight of 40 000) were dissolved in a mixture of 0.5 mL deionized water and 3.5 mL ethanol.…”

“…Potential coating materials range from lithium containing coatings like LiNbO 3 featuring a moderate Li + ion conductivity to insulating and chemically inert materials like Al 2 O 3 , CeO 2 , or ZrO 2 . [ 27–33 ] The coatings enhance the cycling stability of the cathode and, thus, the overall electrochemical performance improves in all cases, regardless of the chemical nature of the coating.…”

“…NCM111 thin films prepared via a sol‐gel process using spin coating act as suitable model system. [ 30 ] The coatings were deposited using atomic layer deposition (ALD). As coating material, we chose Al 2 O 3 as the most common oxide coating [ 39–42 ] as well as CeO 2 , which is currently also considered as a promising coating material.…”

Highly Conductive Polyoxanorbornene‐Based Polymer Electrolyte for Lithium‐Metal Batteries

“…However, a state‐of‐the‐art LIB configuration provides only a cell‐level energy density of ≈ 250 Wh kg −1 , far less than the ICE, which limits the practical usage of LIBs in advanced applications such as electric vehicles and grid storage. [ 3,4 ] Although recent advances and extensive research in LIB technology—including organic electrodes, [ 5–15 ] anode engineering, [ 16–23 ] and new classes of layered metal oxide cathodes [ 24–28 ] —have demonstrated promising performance, the energy density of LIBs continues to be a bottleneck.…”