Effect of Single-Walled Carbon Nanotube Sub-carbon Additives and Graphene Oxide Coating for Enhancing the 5 V LiNi_0.5Mn_1.5O₄ Cathode Material Performance in Lithium-Ion Batteries

Abstract

High-voltage spinel LiNi0.5Mn1.5O4 (LNMO) is a promising cathode material for next-generation lithium-ion batteries (LIBs), but its poor cycle performance has impeded its commercialization. In this study, we developed highly stable LNMO cathode materials having an octahedral morphology through a solid-state high-energy ball-mill–cum–spray-drying method. We also developed a novel strategy for modifying this cathode material with two kinds of carbon materials, thereby improving the electrochemical cycling performance. Introducing single-walled carbon nanotubes (SWCNTs) as a sub-carbon conductive additive during the slurry preparation process improved the conductivity of electrons between the particles of the cathode material. The LNMO electrode modified with the SWCNT sub-carbon additives exhibited an average Coulombic efficiency of 99.4% after 500 cycles at 1C, compared with 98.9% for the pristine LNMO-based electrode. Furthermore, we used a wet-chemical method to coat graphene oxide (GO) onto the post-sintered LNMO cathode material to act as a protective layer, preventing corrosion induced by HF in the electrolyte. The capacity retention of the GO-coated LNMO electrode after 500 cycles at 1C (91.8%) was higher than that of the pristine LNMO (52.5%). The corresponding dual-modification strategy, combining the SWCNTs and GO, provided LNMO cathode materials exhibiting superior rate performance and cyclability, with an average Coulombic efficiency of 99.3% and capacity retention of 92.9% after 500 cycles at 1C. Thus, the LNMO cathode materials prepared in this study possessed excellent electrochemical properties favoring their marketability, applicability, and competitiveness for application in high-voltage LIBs.

Ultrafast Laser Drilling of 3D Porous Current Collectors for High-Capacity Electrodes of Rechargeable Batteries

“…12−16 Innovations on a new material system (for example, high-voltage material) and new battery structure (for example, CTP battery) are lately focused on the design and development of high-performance batteries. 17,18 A current collector is not only the supporter of the above battery materials to constitute an electrode but also the electric pathway that the electron moves during charging/discharging. 19 Nowadays, as the thickness of the Al current collector for the positive electrode decreases from 20 to 8 μm and that of the Cu current collector for the negative electrode decreases from 12 to 5 μm, a 3D micro/nanostructured current collector with enough mechanical property is anticipated to lighten the weight of the current collector that actually does not contribute much capacity, to strengthen the occlusal force between battery materials and the current collector, and to improve the electrolyte penetration as well as ionic diffusivity of alkaline metal ions in the electrode.…”

“…Fe, Mn, V, etc.) have been developed as leading commercial cathode materials, − while graphite/carbon, Li 4 Ti 5 O 12 , and silicon/tin are the common anode materials for commercial batteries. − Innovations on a new material system (for example, high-voltage material) and new battery structure (for example, CTP battery) are lately focused on the design and development of high-performance batteries. , …”