Ferguson Matthew, Egorov Vladimir, Zhang Yan, Gulzar Umair, O'Dwyer Colm
School of Chemistry, University College Cork, Cork T12 YN60, Ireland.
AMBER@CRANN, Trinity College Dublin, Dublin 2 D02 W9K7, Ireland.
ACS Appl Eng Mater. 2025 Mar 1;3(3):613-624. doi: 10.1021/acsaenm.4c00716. eCollection 2025 Mar 28.
The electrochemical response of symmetric carbon-based supercapacitor devices made using two 3D-printing techniques, Vat-P (vat polymerization) and FDM (fused deposition modeling), shows how the printing method dominates the overall cell response. Despite possessing excellent cycle life, the conductive poly(lactic acid) (PLA) FDM printed current collectors suffer from relatively high resistance and suppressed capacitance linked to current collector material resistivity. Here, we examine in situ methods to influence the interfacial conductivity of the FDM current collectors by surface modification. Both dimethylformamide (DMF) and aqueous potassium hydroxide (KOH) treatments are investigated to compare solvent decomposition and electrolyte presoaking for this purpose. Using a single-walled carbon nanotube and graphene nanoplatelet carbon composite slurry on FDM current collectors in Vat-P 3D-printed cell casings, the supercapacitor cells show that the DMF treatment method has worse capacitance but better retention over 1 million cycles compared to the untreated FDM current collector cells. Pretreatment in a solution of 6 M aqueous KOH, identical to the cell electrolyte, markedly improves the effective current collector conductivity and interface with the active material, with a five-fold improvement in capacitance at the expense of less cycling stability. This is possible because the KOH treatment provides a 10-fold reduction in the FDM current collector resistance, which correlates with the improved cyclic voltammetric response. Galvanostatic charge-discharge tests reveal a deteriorated long-term cycling stability and rate capability despite better interfacial conductivity with the active material. In-situ presoaking that allows a degree of depolymerization at the surface relieves the conductive additive within the PLA to improve electrochemical interfacial activity and identifies the trade-off between improved capacitance and long-term cycling stability for common electrolytes in PLA-based 3D printed aqueous supercapacitors.
使用两种3D打印技术（即Vat-P（光聚合）和FDM（熔融沉积建模））制造的对称碳基超级电容器器件的电化学响应表明，打印方法如何主导整个电池的响应。尽管具有出色的循环寿命，但通过FDM打印的导电聚乳酸（PLA）集流体存在相对较高的电阻，并且由于集流体材料的电阻率而导致电容受到抑制。在此，我们研究了通过表面改性来影响FDM集流体界面电导率的原位方法。为此，研究了二甲基甲酰胺（DMF）和氢氧化钾水溶液（KOH）处理，以比较溶剂分解和电解质预浸泡的效果。在Vat-P 3D打印的电池外壳中，将单壁碳纳米管和石墨烯纳米片碳复合材料浆料用于FDM集流体上，超级电容器电池表明，与未处理的FDM集流体电池相比，DMF处理方法的电容较差，但在超过100万次循环中具有更好的保持率。在与电池电解质相同的6M氢氧化钾水溶液中进行预处理，可显著提高有效集流体的电导率以及与活性材料的界面，电容提高了五倍，但循环稳定性有所降低。这是可能的，因为KOH处理使FDM集流体电阻降低了10倍，这与改善的循环伏安响应相关。恒电流充放电测试表明，尽管与活性材料的界面电导率有所提高，但长期循环稳定性和倍率性能却有所下降。允许在表面进行一定程度解聚的原位预浸泡可释放PLA中的导电添加剂，以改善电化学界面活性，并确定了基于PLA的3D打印水系超级电容器中常见电解质在改善电容和长期循环稳定性之间的权衡。
