Cobalt phosphide nanoparticle embedded carbon nanosheet array material as well as preparation and application thereof

Abstract

The invention discloses a cobalt phosphide nanoparticle inlaid carbon nanosheet array material and a preparation and application thereof in a lithium ion battery negative electrode material. The cobalt phosphide nanoparticles are embedded into the carbon nanosheet array material, and the cobalt phosphide nanoparticles are embedded into the carbon nanosheets to form a jujube cake type composite structure; the carbon nanosheets vertically grow on a surface of the foamed nickel to form an array structure. The preparation method comprises the following steps of firstly, growing the ZIF67 nanosheetarray on the surface of the foamed nickel, and then carbonizing and phosphatizing. According to the preparation method, conductivity, structural stability, cycling stability and electrochemical activity of cobalt phosphide can be improved, so cobalt phosphide has higher charge-discharge capacity and more stable cycling performance. The cobalt phosphide nanoparticle embedded carbon nanosheet arrayhas important application value as a lithium ion battery negative electrode material.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to a cobalt phosphide nanoparticle-embedded carbon nanosheet array material and its preparation and application. Background technique [0002] Lithium-ion batteries have the advantages of high energy density and power density, long cycle life, and no memory effect, and are widely used in portable electronic devices and electric vehicles. At present, the negative electrode material of commercial lithium-ion batteries mainly uses graphite, but the theoretical capacity of graphite is only 372mAh g -1 , cannot meet the market demand, and the safety performance of graphite is poor, and the rate performance is low. Therefore, the development of negative electrode materials with higher energy density and better cycle stability is the focus of lithium-ion battery research. [0003] Metal phosphides have a higher specific capacity than graphite and are ideal substitutes for gr...

AI Technical Summary

Problems solved by technology

The patent specification whose publication number is CN111525127A discloses a graphene-based cobalt phosphide negative electrode material and its preparation and application. Two-dimensional graphene oxide (GO) is used as the base material, and ZIF-67 is combined with graphene to combine After the composite material is reduced, the obtained airgel is calcined and phosphated to obtain a graphene-coated cobalt phosphide composite material, but the cobalt phosphide synthesized by this method has a large size and is coated in coarse carbon particles , the lithium storage reaction of cobalt phosphide is severely limited

CoP was reported by LihongXue et al. 3 @PPy nanocube materials (Qing Liu, Yu Luo, Weilun Chen, Youwei Yan, Lihong Xue, Wuxing Zhang, Chemical Engineering Journal 347(2018) 455-461), they made the precursor cubic Co 3 [Co(CN) 6 ] 2 Phosphated into cobalt phosphide and then coated with a layer of PPy, this material also has CoP 3 The problem of oversizing, CoP 3 The cube size reaches about 2 μm, which is obviously not conducive to the lithium storage reaction, and the stability is poor

At present, the research progress of cobalt phosphide in the field of lithium-ion batteries is relatively slow, and new breakthroughs are needed in nanostructure design and composite high-conductivity materials.

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