Constructing a Highly Efficient Aligned Conductive Network to Facilitate Depolarized High‐Areal‐Capacity Electrodes in Li‐Ion Batteries

Abstract

In order to prepare electrodes with high mass loading and areal capacities, the key issue is to achieve depolarization for both ion and electron transfer on the electrode material surface. In this work, through copolymerization of xanthan gum (XG) and amorphophallus konjac gum (KG) followed by an ice‐templating method, aligned electrodes with high areal mass loading of active materials are prepared. In addition to firmly holding active materials together, the prepared KG–XG copolymer also facilitates improved effective porosity as well as homogeneous dispersion of conductive agents (i.e., CNTs). Consequently, with minimum inactive components (i.e., binder and conductive agents), the proposed electrode structure delivers good cycling stability and rate capability under high areal loading (as high as 200 mg cm−2). The excellent electrochemical performance can be attributed to the unique aligned structure where the robust conductive network provides an efficient electron and lithium‐ion pathway, and the homogenous porosity is beneficial for the electrolyte percolation, hence the reduced polarization during charge transfer. In addition, this electrode preparation method is found to be universal as it is suitable for various types of anode and cathode materials.

Ultrahigh-Capacity and Scalable Architected Battery Electrodes via Tortuosity Modulation

“…The low-tortuosity pores aligned in the depth direction of the electrode reduce Li + diffusion distance and facilitate Li + diffusion inside pores, which is a rate-limiting process in thick electrodes. Aligned electrode structures have been constructed by employing external forces such as magnetic field, , temperature field, − and evaporation flow or by introducing conductive templates including carbonized wood, , graphene nanosheets, , and carbon nanofibers . The prior work promotes the understanding of multiscale transport kinetics and advances rational engineering of porous electrodes.…”

Shape-stabilized phase change composites enabled by lightweight and bio-inspired interconnecting carbon aerogels for efficient energy storage and photo-thermal conversion

“…34,35 The introduction of XG, which is a green and inexpensive biomass resource, can improve the structural and mechanical stability of PI-based carbon aerogels, and ensure the uniform dispersion of TiO 2 nanoparticles in the aerogel. 36 Moreover, the synergistic effect of the three components can create a connected thermally conductive network for composite PCMs, 30,37 which is vital for regulating the structural morphology and realizing high thermal conductivity, good thermal cycling stability, and excellent photo-thermal conversion properties of the material.…”

A Hierarchical Si/C Nanocomposite of Stable Conductive Network Formed Through Thermal Phase Separation of Asphaltenes for High‐Performance Li‐Ion Batteries

“…Although physical mixing of active materials and conductive additives during the battery assembly could improve the conductivity to some degree, it remains suffering from the limited conductivity of ions and electrons, thereby increasing the polarization of the electrode. [ 8 ] By providing a 2D conductive carbon framework which is stably connected to the carbon coatings as a matrix, the improvement of the conductive network is anticipated to further enhance the cyclability of the electrode and the operation under high mass loadings. [ 16 ] Herein, we report a low‐cost and scalable synthesis route for a hierarchical Si/C nanocomposite of a conductive and robust carbon matrix with silicon nanoparticles being uniformly imbedded in situ in the matrix during the synthesis.…”

“…[4][5][6] The poor intrinsic conductivity of silicon and poor electric connection between silicon and conductive matrix on the other hand hinder severely the stable operation of Si electrodes, particularly at a high rate or mass loading. [5] To realize the commercial application of silicon-based anodes, it is necessary to consider simultaneously the following requirements: i) a robust protective layer on the silicon surface to prevent persistent reaction between silicon and electrolyte; [7] ii) strong and homogenous connections between silicon and conductive networks to minimize local stress-strain and conduction loss for the electrode structure; [6] iii) fast ion/electron transfer for stable operation at a high rate or mass loading; [8][9] and more importantly iv) a simple and low-cost commercial synthesis route.…”

“…[10][11][12] Due to its high mechanical strength and conductivity, carbon-based materials have been widely used to enhance the conductivity of silicon and as a protective layer to alleviate the detrimental effect of silicon expansion. [10,13] Hierarchical structures combining carbon coatings with other carbon-based conductive materials, such as carbon nanotubes, [8][9]14] carbon nanosheets [15][16][17][18] and graphene [19][20][21] have been proposed to construct a robust protection layer to accommodate the volume change and a conductive network to maintain the integrity of electrode structures. However, the silicon particles and these carbon materials are often mixed by physical methods.…”