导电炭黑分散性难题迎来全新突破！

【炭黑产业网】消息，近日，四川轻化工大学材料科学与工程学院陈建教授团队在导电炭黑领域取得重要突破，相关研究成果以题为《Additive-Free Homogeneous Dispersion of Conductive Carbon Black via Electrostatic Repulsion for High-Performance Lithium-Ion Batteries》发表于国际权威期刊《ACS Sustainable Chemistry & Engineering》（IF: 7.6，中科院一区Top）。四川轻化工大学为第一通讯单位，陈建教授为通讯作者。

据炭黑产业网了解，该研究聚焦导电炭黑在锂离子电池应用中的分散难题，提出了一种基于静电作用的绿色分散新策略。在陈建教授指导下，李瑞博士带领硕士研究生郑伟月通过引入高压静电场，实现了导电炭黑在活性物质中的快速均匀分散，有效避免了传统方法中因添加分散剂或采用高强度机械混合所导致的浆料稳定性下降和充放电过程可能引发副反应的问题，为导电炭黑的分散工艺提供了一种快速、可控、可规模化的新路径。

团队创新性地将静电纺丝设备产生的高压电场施加于磷酸铁锂、导电炭黑与N-甲基吡咯烷酮构成的混合体系中。在电场作用下，附着于电极接触区域的链状导电炭黑末端因同种电荷排斥而发生快速分离，并在持续搅拌过程中均匀包覆于磷酸铁锂表面，从而实现导电炭黑与活性物质的高效复合。该过程不产生高温、不引入额外添加剂，对导电炭黑及活性物质的物理化学性质无不利影响。

Fig. 1.

HV-EF-assisted carbon black dispersion and schematic of the experimental setup.

借助Materials Studio完成50ns分子动力学仿真，从分子尺度验证高压静电分散方案的可行性：施加高压静电场后体系总能量下降约38%，炭黑分散体系热力学稳定性显著提升；分子构型对比可见，无电场条件下炭黑紧密团聚堆积，施加电场后炭黑颗粒彼此分离并均匀分散在磷酸铁锂基体中，从理论层面证明静电斥力能够有效破除炭黑团聚结构。

Fig. 2. HV-EF-assisted dispersion mechanism and validation.

(a) Electrochemical cycling performance of LFP half-cells using electrodes prepared with different carbon black dispersion methods. (b) Schematic illustration of electrostatic effects: hair standing from static charge and electrospinning for nanofiber fabrication. (c-e) Molecular structure models: (c) LFP, (d) N-methyl-2-pyrrolidone (NMP) solvent, and (e) carbon black. (f) Simulated vector distribution of the electrostatic field. (g) Evolution of the total system energy with and without the applied electrostatic field. (h,i) Simulated molecular arrangements: (h) with and (i) without the electrostatic field, corresponding to the dispersed and agglomerated states of carbon black particles, respectively.

采用粒度、拉曼、SEM、XRD、FTIR、接触角多项表征，对比静电处理ER组与常规搅拌CG组微观结构：静电场可使炭黑中位粒径D50下降15.14%，彻底消除大团聚体，拉曼测试证明炭黑在极片内分布均匀度大幅提升；SEM直观显示对照组炭黑结块、磷酸铁锂颗粒裸露、导电网络断裂，而ER组无明显团聚，仅5wt%炭黑即可完整包覆活性材料，工艺还适配碳纳米管类导电剂；XRD、FTIR结果证实静电处理不会破坏磷酸铁锂晶体结构与炭黑表面化学性质，不改变材料本征性能；同时电极接触角波动显著减小，极片表面疏水分布均匀，解决了传统浆料涂覆厚薄不一、极片掉料的工艺难题。

Fig. 3.

(a) Particle size distribution. (b) Raman spectra. (c) Fluctuation fitting of the ID/IGratio. (d-f) SEM images of carbon black/LFPmixed powders with carbon black contents of (d) 10 wt%, (e) 7.5 wt%, and (f) 5 wt% before electrostatic-field-treatment. (g-i) SEM images of the corresponding mixed powders after electrostatic-field-assisted stirring. (j) Contact angle measurements. (k) FTIR spectra. (l) XRD patterns.

组装CR2032扣式半电池、全电池，并开展常温、低温（5℃）性能测试，核心数据优势突出：低炭黑添加5wt%工况（行业降本、提能量密度主流方向）：0.5C放电容量提升12mAhg-1，1C提升32mAg-1，充放电极化间隙大幅缩小，大电流下动力学优势更明显；10wt%炭黑体系200圈长循环：0.5C容量高4.8mAhg-1、1C容量高7.5mAhg-1；全电池测试中ER样品全倍率容量持续优于对照组；低温5℃测试：低温下离子扩散主导阻抗，两组性能差距缩小，但静电处理电极循环稳定性、充放电极化仍显著优于传统工艺。

Fig. 4. Enhanced electrochemical performance via HV-EF-assisted dispersion.

(a, b) Comparative (a) rate capability and (b) cycling stability of LFP electrodes with 10 wt% conductive carbon black, prepared with (ER) and without (CG) HV-EF treatment. (c, d) The corresponding (c) rate and (d) cycling performance for electrodes with a reduced additive content of 5 wt%. (e) Galvanostatic charge-discharge profiles highlighting the reduced polarization in the 5 wt% ER electrode. (f) Full-cell performance employing the optimized LFP cathode (10 wt% additive). (g,h) (g) Low-temperature (5 °C) rate performance and (h) associated charge-discharge profiles of the 10 wt% electrodes.

通过多类导电与界面阻抗表征可明确静电处理带来的电极性能优势：四点探针测试证实，2.5wt%至10wt%全区间炭黑添加量下，ER组电极电阻分布更集中，电极内部导电网络整体均匀；KPFM表征量化得出ER5%电极表面电势波动相比CG5%降低29.17%，极片电位分布更均衡，能减少充放电时局部析锂、微短路等安全隐患；EIS-DRT解析结果显示，决定电池内阻的颗粒接触电阻 τ₁大幅降低，ER5%接触阻抗仅为对照组CG5%的一半，且锂离子扩散系数同步提升，电极离子传导动力学得到整体优化。

Fig. 5. Multiscale analysis of electrode properties.

(a-d) Four-point-probe conductivity mapping of composite electrodes with conductive carbon black loadings of (a) 10 wt%, (b) 7.5 wt%, (c) 5 wt%, and (d) 2.5 wt%. (e-j) Kelvin probe force microscopy (KPFM) analysis: (e, f) surface topography and (g) corresponding surface potential distribution of the CG5% electrode; (h,i) topography and (j) surface potential distribution of the ER5% electrode for comparison. (k-m) Electrochemical kinetics analysis: (k) Nyquist plots from electrochemical impedance spectroscopy (EIS), (l) distribution of relaxation times (DRT) deconvolution for electrodes with 10 wt% and 5 wt% carbon black, and (m) galvanostatic intermittent titration technique (GITT) profiles for lithium-ion diffusion coefficient determination.

实验结果表明，在相同导电炭黑添加比例下，该方法显著提升了电极表面的电势均匀性与循环比容量，验证了其在实际电池体系中的应用潜力。