Electrode-supported high-tortuosity zeolite separator enabling fast-charging and dendrite-free lithium-ion/metal batteries

Lithium-metal batteries (LMBs) are poised to be the next-generation high-energy density storage media of choice for various applications; however, they are currently plagued by failure due to dendrite propagation at high charge/discharge rates. One of the most sought-after technologies for dendrite propagation prevention in LMBs is solid state batteries, but they face commercialization challenges due to low room temperature ionic conductivity and high manufacturing cost. Here, we report the use of plate-shaped zeolite particles with intraparticle crystalline micropores to form an electrode-coated separator by a scalable blade-coating methodology. These separators with minimal polymer content are non-flammable and highly wettable to organic-based liquid electrolytes. They have high pore tortuosity and shear modulus resulting from the unique physical properties and morphology of the plate-shaped zeolite particles. LMB cells made of a LiNi_0.5Co_0.2Mn_0.3O₂ (NMC) cathode, coated with the plate-shaped zeolite separator, LiPF₆-carbonate electrolyte, and lithium metal anode, show good charge-discharge characteristics and effectiveness in preventing dendrites from propagating through the separator even at high (3 C-rate) rates. When compared to LMB cells with a tortuously porous separator of similar pore size and porosity made of dense plate-shaped γ-alumina particles without intraparticle pores, cells with the zeolite separator show better charge/discharge characteristics, lower solid electrolyte interface (SEI) and charge-transfer resistances, and more effective dendrite propagation prevention. Results suggest that the intraparticle pores of the zeolite separator particles homogenize the Li-ion flux at the separator-anode interface in a much better manner than γ-alumina particles. There is promising commercial potential for the electrode-coated zeolite separator with highly tortuous pores for lithium batteries with a lithium-metal anode.