Scalable Manufacture of High‐Performance Battery Electrodes Enabled by a Template‐Free Method

Abstract

Ion transport kinetics is identified as the major challenge of thick electrode design for high‐energy‐density lithium‐ion batteries. The introduction of vertically‐oriented structure pores, which provide fast transport pathways for Li+, can maximize the rate‐performance of electrodes while holding a high energy density. To overcome the harsh manufacturing requirements of traditional template‐based methods for the oriented‐pore electrodes, a template‐free strategy is developed to meet the large‐scale fabrication demand, in which controllable oriented microchannels are facilely constructed by vertically aggregated bubbles generated from thermal decomposition. The proposed method is demonstrated to be applicable for different active materials and compatible with industrial roll‐to‐roll manufacturing. The oriented‐pore electrodes exhibit a seven times higher capacity at 5C rate and show double the power density relative to the state of the art while maintaining a high level of energy density. The balance between the ion transport kinetics through the channels and in the matrix manifests an optimal design of the electrode structures, enabling the desired superior performance of the electrodes toward practical applications.

Molecular Insights into the Structure and Property Variation of the Pressure-Induced Solid Electrolyte Interphase on a Lithium Metal Anode

“…The SEI thickness significantly decreases with the pressure, and the thinner SEI can accelerate the Li + transport process at subsequent charge/discharge cycles, consequently reducing the polarization degree of the Li-metal/electrolyte interface and the Li dendrite growth. The SEI growth limited by the pressure can be ascribed to the local pore closure and less available electrolyte at the interface. , Meanwhile, as the tension promotes the lateral growth of the SEI and generates pores and even cracks (discussed in detail below), the SEI thickness under tension shows a faster growth rate than that under pressure at the growth stage.…”

“…The SEI growth limited by the pressure can be ascribed to the local pore closure and less available electrolyte at the interface. 45,46 Meanwhile, as the tension promotes the lateral growth of the SEI and generates pores and even cracks (discussed in detail below), the SEI thickness under tension shows a faster growth rate than that under pressure at the growth stage.…”

Low Tortuosity and Reinforced Concrete Type Ultra‐Thick Electrode for Practical Lithium–Sulfur Batteries

“…Furthermore, the aligned channel structures are destroyed at high compaction density as shown in the cross‐section SEM image of the FD/C electrode in Figure S15, Supporting Information, suggesting that the low‐tortuosity structure in the ultra‐thick electrode is a key limiting factor to achieve excellent electrochemical performance. [ 16 ] Moreover, the FD/C electrode can reach an ultrahigh loading amount of 30.4 mg cm −2 and deliver the highest initial areal capacity of 18.8 mAh cm −2 after the first activation cycle with and displays a high areal capacity up to 12.9 mAh cm −2 over 30 cycles with a capacity retention of 88% ( Figure a).…”

Roadmap on Li-ion battery manufacturing research

“…Nevertheless, there are limitations for NaCl templating, notably the fact that it requires water dissolution for the removal of the NaCl templates, which is challenging for some water-sensitive electrodes, like high-Ni content NMC cathodes. To overcome this issue, recent work has used NH 4 HCO 3 particles as the template which can be removed by low-temperature heat treatment, providing a promising alternative solution in this area [93]. Other templating methodologies, like wood and magnetic-assisted templating, have also been proposed in the literature [94,95].…”