TY - JOUR AU - Homann, Gerrit AU - Stolz, Lukas AU - Neuhaus, Kerstin AU - Winter, Martin AU - Kasnatscheew, Johannes TI - Effective Optimization of High Voltage Solid‐State Lithium Batteries by Using Poly(ethylene oxide)‐Based Polymer Electrolyte with Semi‐Interpenetrating Network JO - Advanced functional materials VL - 30 IS - 46 SN - 1616-3028 CY - Weinheim PB - Wiley-VCH M1 - FZJ-2020-02949 SP - 2006289 - PY - 2020 AB - Solid polymer electrolytes (SPEs) are promising candidates for the realization of lithium metal batteries. However, the popular SPE based on poly(ethylene oxide) (PEO) reveals a “voltage noise”‐failure during charge, for example, with high energy/high voltage electrodes like LiNi0.6Mn0.2Co0.2O2 (NMC622), which can be attributed to short‐circuits via penetrating Li dendrites. This failure disappears when integrating PEO‐based SPE in a semi interpenetrating network, which mainly consists of PEO units, as well. In this work, it is shown that this SPE allows performance improvement via elimination of the crystalline domains without significant sacrifice of mechanical integrity. Hence, a highly amorphous SPE can be obtained by a simple increase of plasticizing Li salts, which overall is beneficial, not only for the ionic conductivity, but also the homogeneity, while remaining mechanically stable and solid in its original shape even after storage at 60 °C for 7 days. These aspects are crucial for the performance of the modified SPE as they can suppress the failure‐causing Li dendrite penetration while the electrochemical aspects, that is, anodic stability, are rather unaffected by the modification and remain stable (4.6 V vs Li│Li+). Overall, this optimized SPE enables stable cycling performance in NMC622│SPE│Li cells, even at 40 °C operation temperature. LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000563908700001 DO - DOI:10.1002/adfm.202006289 UR - https://juser.fz-juelich.de/record/878611 ER -