Design Strategies toward High‐Performance Hybrid Carbon Bilayer Anode for Improved Ion Transport and Reaction Stability

Abstract

Compositing carbon‐based materials with different properties can significantly improve the energy density of lithium‐ion batteries for applications that require high power, such as electric vehicles, owing to their effective current distribution. Nevertheless, the chemical reaction is not uniform throughout the entire depth of conventionally blended electrodes. This study proposes a hybrid patterned bilayer anode that comprises a blended layer of spherical crystalline graphite (SCG) and soft carbon and a single layer of SCG alone, which maintains a stable ionic reaction at the electrode surface and improves ion transport. This bilayer anode has a smaller, more uniform solid electrolyte interphase layer that is more evenly distributed throughout the electrode compared with the blended electrode. The electrode pattern interfaces, which are optimized by controlling the pattern size, ensure excellent mechanical adhesion and low internal resistance. Consequently, the patterned bilayer half‐cell achieves a high‐capacity retention of 85.9% after 500 charge–discharge cycles at 1 C. The full cell also attains an energy density of 178.7 Wh kg−1 with fast discharging at 10 C, which is 2.3 times higher than that of the single‐layer SCG electrode.

Toward practical anode-free lithium pouch batteries

“…A promising way is to learn established methods of study in the field of LIBs, for instance, heat production characterization and electricity distribution pattern. [103][104][105] Moreover, AFLPB modules and regulation systems should be designed for actual applications. Both life prediction and recycling of AFLPBs are worth following.…”

A Multilayer Doyle-Fuller-Newman Model to Optimise the Rate Performance of Bilayer Cathodes in Li Ion Batteries

“…These include different AM particle diameters in different regions, both in graded and layered arrangements, different porosity fractions in different regions, or different proportions of AM:C:B from place to place. 6,7,[10][11][12][13][14][15][16] For the specific case of electrode bilayers (an electrode made of two distinct sub-layers), studies have mainly focused on two layers of the same active material but with, for example, different particle diameters or volume fractions in each layer. 6,[10][11][12] Generally, the rationale is to homogenise the rate of charge/discharge across the electrode thickness, by having a heterogeneous structure spatially tailored to avoid local over-provision, or under-provision, of Li ions, for energy storage reactions.…”

“…6,7,[10][11][12][13][14][15][16] For the specific case of electrode bilayers (an electrode made of two distinct sub-layers), studies have mainly focused on two layers of the same active material but with, for example, different particle diameters or volume fractions in each layer. 6,[10][11][12] Generally, the rationale is to homogenise the rate of charge/discharge across the electrode thickness, by having a heterogeneous structure spatially tailored to avoid local over-provision, or under-provision, of Li ions, for energy storage reactions. For example, when a bilayer graphite negative electrode was used, cell capacity retention was improved compared with a chemically similar but homogeneous electrode.…”