biostudies-literatureHestenes JCU.S. Department of DefenseDivision of Chemical, Bioengineering, Environmental, and Transport SystemsDivision of Graduate Education88-101https://www.ebi.ac.uk/biostudies/studies/S-EPMC9999480biostudies-literatureUnknown3(2)The high-voltage LiNi_0.5Mn_1.5O₄ (LNMO) spinel cathode material offers high energy density storage capabilities without the use of costly Co that is prevalent in other Li-ion battery chemistries (e.g., LiNi_<i>x</i>Mn_<i>y</i>Co_<i>z</i>O₂ (NMC)). Unfortunately, LNMO-containing batteries suffer from poor cycling performance because of the intrinsically coupled processes of electrolyte oxidation and transition metal dissolution that occurs at high voltage. In this work, we use operando electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) spectroscopies to demonstrate that transition metal dissolution in LNMO is tightly coupled to HF formation (and thus, electrolyte oxidation reactions as detected ACS materials AuTransition Metal Dissolution Mechanisms and Impacts on Electronic Conductivity in Composite LiNi_0.5Mn_1.5O₄ Cathode Films.PMC99994802021278071CBET-2045262Marbella LEHestenes JCSadowski JTMay RfalseTransition Metal Dissolution Mechanisms and Impacts on Electronic Conductivity in Composite LiNi_0.5Mn_1.5O₄ Cathode Films.The high-voltage LiNi_0.5Mn_1.5O₄ (LNMO) spinel cathode material offers high energy density storage capabilities without the use of costly Co that is prevalent in other Li-ion battery chemistries (e.g., LiNi_<i>x</i>Mn_<i>y</i>Co_<i>z</i>O₂ (NMC)). Unfortunately, LNMO-containing batteries suffer from poor cycling performance because of the intrinsically coupled processes of electrolyte oxidation and transition metal dissolution that occurs at high voltage. In this work, we use operando electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) spectroscopies to demonstrate that transition metal dissolution in LNMO is tightly coupled to HF formation (and thus, electrolyte oxidation reactions as detected 2023-01-01T00:00:00Z2023 Mar2025-04-19T04:09:33.763Z2025-04-19T04:09:33.763ZS-EPMC99994803808972410.1021/acsmaterialsau.2c00060