A General Multi‐Interface Strategy toward Densified Carbon Materials with Enhanced Comprehensive Electrochemical Performance for Li/Na‐Ion Batteries

Abstract

power density. [1,2] Among all the materials, carbon materials including graphite, hard carbon and soft carbon are the usually commercialized products owing to the stable structure, desirable specific capacity, controllable morphology, low cost and low toxicity. [3][4][5] However, there is a great challenge to realize the unification of both high gravimetric/volumetric capacity and high rate performance for carbon anode materials.The improvement of rate performance of carbon anode materials is dominated by the ion and electron diffusion kinetics. For the ion diffusion process, nanostructure, porous or hollow structure can shorten the ion diffusion distance, while the enlarged carbon layer distance can reduce the ion diffusion resistance. [6][7][8][9] All the above structures can effectively facilitate the ion diffusion kinetics. Xu et al. prepared 3D graphene foams with plenty of pores, large surface area, and enlarged interlayer distance between graphene layers, which presents the superior rate capability of 137.7 mA h g -1 at the high current density of 5 A g -1 as anode materials in SIBs. [10] However, all the above methods inevitably result in the high surface area and low packing density, which will finally lead to the low initial coulombic efficiency (ICE) and unsatisfactory volumetric specific capacity. Increasing the electronic conductivity is another strategy to improve rate performance. Carbon nanotubes and graphene are usually used as the conductive agents to enhance the electrical property of electrode materials and further the high-rate performance of batteries. [11][12][13][14][15] Zhu et al. prepared graphene-scaffolded silicon/ graphite composite with graphene hydrogel, which present increased rate capability than the silicon/graphite composite. [14] Nevertheless, these conductive networks can only improve the surface electronic conductivity among the common micro-sized particles, and fail to increase the inner conductivity. In fact, some recent works suggest that the planar structure of graphene may block the shortest diffusion path for ion and finally increase the ion diffusion impedance. [16,17] It is still a great challenge to realize the comprehensive improvement of the electrochemical performance, especially the rate performance and high density synchronous improvement, for the electrode materials.Fast charging rate and large energy storage are key requirements for lithiumion batteries (LIBs) in electric vehicles. Developing electrode materials with high volumetric and gravimetric capacity that could be operated at a high rate is the most challenging problem. In this work, a general multi-interface strategy toward densified carbon materials with enhanced comprehensive electrochemical performance for Li/Na-ion batteries is proposed. The mixture of graphene oxide and sucrose solution is sprayed into a water/oil system and furtherly carbonized to get graphene/hard carbon spheres (GHSs). In this material, abundant ingenious internal interfaces between the crystalline graphene and the carbon matr...

Insight into the structural evolution mechanism and potassium storage performance of expanded graphitic onion-like carbon

“…1e), the (002) peak of NFG is sharper than that of GOC, indicating that NFG has higher crystallinity. 30 The higher average thickness ( L c ), basal plane width ( L a ), degree of graphitization ( G ) and lower interlayer spacing ( d 002 ) of NFG further demonstrate that NFG has a larger sized graphite domain and higher order degree of the crystal structure than GOC (Table S1†). 31 The Raman spectra of NFG and GOC (Fig.…”

Advances in Carbon Materials for Sodium and Potassium Storage

“…Yuan et al also developed a multi-interface assembly strategy to fabricate graphene/hard carbon composites with multi-interphase structure (Figure 34d), which was composed of densified microspheres embedded with curved and wrinkled graphene nanosheets, contributing to both high packing density and effective electrode/electrolyte contact. [376] The specific capacities were measured to be 302.5 mAh g -1 with around 275 mAh cm -3 at 0.05 A g -1 . Except spherical carbons, the folded carbon with a highly packed integrated lamellar structure is also effective for high volumetric performance.…”

“…Reproduced with permission. [376] Copyright 2022, Wiley-VCH. e) Scheme of the densified 3D folded graphene electrode.…”

“…d) Scheme of densified carbon microspheres with multi-interphase structure. Reproduced with permission [376]. Copyright 2022, Wiley-VCH.…”

Novel Bimetallic Activated Center Alloying Mechanism Positive Electrodes for Aluminum Storage

“…[1] In this background, widespread attention has been attracted on building a low carbon society rooted in renewable energy sources (e.g., wind energy, solar energy). [2,3] However, renewable energy sources have the disadvantages of intermittency, instability, and geographical constraints, which inevitably requires a high-safety, environment friendly, and low-cost electrochemical energy storage system that can cater for the deformity of renewable energy sources. [4][5][6] As the state-of-theart energy storage devices, lithium-ion batteries (LIBs) have…”