Carbon primer layer morphological effect on the lithium manganese iron phosphate positive electrode performances for lithium-ion batteries

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 973; p. 118661
• Main Authors: Kim, Wontak, Kim, Miseung, Ho Song, Jun, Yu, Ji-Sang, Kim, Hyun-seung
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.11.2024
• Subjects: Aluminum current collector; Carbon primer coating layer; Initial resistance; Lithium manganese iron phosphate; Lithium-ion batteries; Lithium-ion batteries; Carbon primer coating layer; Lithium manganese iron phosphate; Aluminum current collector; Initial resistance
• ISSN: 1572-6657
• DOI: 10.1016/j.jelechem.2024.118661

•Void in carbon primer layer hinders effective contact with Al and electrode mass.•Graphene-type primer has no voids, and hence minimizes contact resistance.•Cycle and power performances are improved with graphene-type primer layer. The application of lithium manganese iron phosphate (LMFP) electrodes is important for enhancing the energy density of phosphate-based positive electrodes. However, their practical implementation is hindered by the deteriorating collector–electrode interface caused by submicron-sized particles with carbon-coated surfaces of LMFP. The morphology of carbon particles on current collector affects the efficiency of the primer layer, despite its role in strengthening the electrical contact between LMFP and the aluminum (Al) current collector. Incorporating carbon nanotube (CNT)-type carbon into the primer layer weakens the electrical connection between the electrode mass and current collector, indicating that CNT-coated Al does not effectively reduce contact resistance. In contrast, the planar shape of graphene-type carbon provides a more effective connection between LMFP and the Al plate, resulting in minimal contact resistance. This improvement in contact resistance enhances cycleability by significantly reducing polarization during cycling, which prevents electrolyte decomposition on the LMFP surface. Given the significant impact of carbon morphology on interfacial contact, it is essential to rationally control the morphology of the carbon primer layer to optimize the properties of the positive electrode.