新能源电池领域导电剂技术的研究与产业化

Research and industrialization of conductive additive technology in the field of new energy batteries

二次电池已经被广泛开发并应用于各种领域,如大规模储能、便携式电子设备和电动汽车。作为锂离子电池的重要组成部分,主要通过构建导电网络来增加和保持电极的电子导电性,从而有效改善电池的电化学性能。导电剂虽然在锂离子电池成本的占比较小(2%左右),但相比于数十万亿级别的锂离子电池产业,导电剂也随之成为了千亿级别的产业。目前,主流导电剂为炭黑类、导电石墨类、气相生长碳纤维(VGCF)、碳纳米管和石墨烯。其中,炭黑类、导电石墨类和VGCF作为传统导电剂,其在活性物质间可形成点、线接触式导电网络;碳纳米管和石墨烯属于新型导电剂材料,其可分别形成线、面接触式导电网络。相对于单一导电剂,复合导电剂可使不同导电剂之间产生协同效应,从而表现出更优异的性能,因此新型导电剂与传统导电剂是高度统一的关系,在成本及性能的综合考量下,未来导电剂体系将逐步从单一化走向多元复合化。此外,我国导电剂长期依赖进口,近年来一些优秀企业在制备方法和分散技术方面逐步打破工艺壁垒,加速国产化进程。本工作将讨论碳纳米材料作为导电剂用于电池领域并改善电池电化学性能的相关工作,并进一步讨论导电剂的产业化现状前景。要点:(1)总结了导电剂对锂离子电池性能的影响。(2)介绍了导电剂的分散技术。(3)归纳了导电剂的制备方法。(4)讨论了导电剂的产业化现状和前景。

Secondary batteries have been widely developed and used in various fields,such as large-scale energy storage,portable electronic devices,and electric vehicles.Conductive additives,as an important component of lithium-ion batteries,could increase and maintain the electronic conductivity of the electrodes by constructing a conductive network,which will effectively improve the electrochemical performance of batteries.Although conductive additives account for a relatively small proportion of the cost of lithium batteries(around 2%),compared to the trillion level lithium battery industry,conductive additives have also become a trillion level industry.At present,the mainstream conductive additives are carbon black,conductive graphite,vapor grown carbon fiber(VGCF),carbon nanotubes,and graphene.They are ideal conductive additives for lithium-ion batteries because of superior properties such as low weight,high chemical inertness,and high specific surface area.Among them,carbon black,conductive graphite,and VGCF are traditional conductive additive materials that form point and line contact conductive networks between active materials;carbon nanotubes and graphene belong to new conductive additive materials,which respectively form wire and surface contact conductive networks between active materials.Compared to a single conductive agent,composite conductive agents create synergistic effects between different conductive agents,thus exhibiting better performance.Therefore,we believe that the new conductive agent has a highly unified relationship with traditional conductive agents.Taking into account both cost and performance,the future conductive agent system will gradually shift from singularity to multiple composites.In addition,China's conductive agents have long relied on imports.In recent years,some excellent enterprises have gradually broken through process barriers in preparation methods and dispersion technologies,accelerating the process of localization.This article will discuss the related work of using carbon nanomaterials as conductive additives in the field of batteries and improving their electrochemical performance.Then,further discuss the industrialization status and prospects of conductive additives.Key learning points:(1) The effect of conductive additives on the performance of lithium-ion batteries is summarized.(2) The dispersion technology of conductive additives is introduced.(3) The preparation methods of conductive additives is summarized.(4) The industrialization status and prospects of conductive additives are discussed.