High Volumetric Energy and Power Density Li2TiSiO5 Battery Anodes via Graphene Functionalization

Abstract

As a Li-ion battery anode, Li 2 TiSiO 5 nanoparticles are conformally coated with graphene using a scalable ethyl cellulose-based solution process, which enables low overpotential and charge-transfer resistance, resulting in high rate performance with minimal risk for Li dendrite growth. Furthermore, the ethyl cellulose-based solution processing enables dense electrode packing and thus exceptionally high volumetric energy densities. With these advantages, graphenefunctionalized Li 2 TiSiO 5 shows significant potential as a next-generation Li-ion battery anode for high volumetric energy and power density applications.

Elucidating and Mitigating High-Voltage Interfacial Chemomechanical Degradation of Nickel-Rich Lithium-Ion Battery Cathodes via Conformal Graphene Coating

“…Although the NMC-GrEC electrode contained no additional polymeric binder, the MWCNTs and the conductive carbon residue formed by the decomposition of the ethyl cellulose together acted as the binding components in the electrode. Consequently, no film delamination was observed during casting and drying, which was consistent with previous reports. , The average active material loadings for both the NMC-CBPVDF and the NMC-GrEC electrodes were maintained at ∼3 mg cm –2 . Electrode discs were punched out and calendered with approximately 6 MPa applied pressure.…”

“…Following synthesis, the NMC particles were uniformly coated with graphene and ethyl cellulose (GrEC) using a previously established solution-phase method. 25,27 The coating conformality was confirmed using SEM and transmission electron microscopy (TEM) (Figure 1a−c), which revealed the presence of a percolating network of graphene flakes throughout the electrode, consistent with prior work. 25,27,28 After fabricating electrodes with the GrEC powder (NMC-GrEC), the electrode was heated to pyrolyze the ethyl cellulose (EC) polymer, which largely volatilizes the EC, compacts the electrode, and generates a carbon residue that helps form a percolating, electrically conductive network among the graphene-coated NMC particles.…”

“…25,27 The coating conformality was confirmed using SEM and transmission electron microscopy (TEM) (Figure 1a−c), which revealed the presence of a percolating network of graphene flakes throughout the electrode, consistent with prior work. 25,27,28 After fabricating electrodes with the GrEC powder (NMC-GrEC), the electrode was heated to pyrolyze the ethyl cellulose (EC) polymer, which largely volatilizes the EC, compacts the electrode, and generates a carbon residue that helps form a percolating, electrically conductive network among the graphene-coated NMC particles. 24,25,27−30 Subsequent Raman spectroscopy of the electrode confirmed that the ratio of the D and G peaks decreased (at 1350 and 1580 cm −1 , respectively) (Figure S3), suggesting that EC decomposition resulted in a more graphitic carbon network that facilitates efficient charge transfer.…”

“…Consequently, no film delamination was observed during casting and drying, which was consistent with previous reports. 25,27 The average active material loadings for both the NMC-CBPVDF and the NMC-GrEC electrodes were maintained at ∼3 mg cm −2 . Electrode discs were punched out and calendered with approximately 6 MPa applied pressure.…”

Layered Perovskite Lithium Yttrium Titanate as a Low‐Potential and Ultrahigh‐Rate Anode for Lithium‐Ion Batteries

“…The comparison of rate performance between LYTO and other high‐profile Ti‐based and Nb‐based anode materials is shown in Figure 2e. It is obvious that the rate capacity of LYTO anode significantly surpasses that of the listed titanium‐based anode materials, including the well‐constructed Li 4 Ti 5 O 12 , [ 37 ] graphene functionalized Li 2 TiSiO 5 , [ 38 ] Li 0.5 La 0.5 TiO 3 , [ 39 ] 1D TiNb 2 O 7 nanorods, [ 40 ] and porous nanosized Ti 2 Nb 10 O 29 . [ 41 ] Even compared to several high‐rate niobium‐based anode materials, such as T‐Nb 2 O 5 , [ 23 ] Li 0.1 La 0.3 NbO 3 , [ 42 ] Nb 14 W 3 O 44 , [ 43 ] and Nb 18 W 16 O 93 , [ 20 ] LYTO anode exhibits the comparable rate performance, demonstrating the ultrahigh‐rate properties.…”