提出了利用挤出式3D打印技术制备孔隙扭曲度=1的超厚分级孔锂离子电池电极的新方法。并采用质量浓度为80 mg/mL的氧化石墨烯作黏度调节剂，磷酸铁锂作电极活性材料，配制了具有可打印性的"墨水"，其表观黏度高达10⁴ Pa·s，并且表现出明显的剪切变稀行为；同时此"墨水"还具有高达10⁴ Pa的存储模量平台值，这些优异的流变学性质对于打印和固化过程十分有利，保证了打印结构的精准与完整性。电化学测试结果表明，与活性物质负载量同为21 mg/cm²的传统涂覆式电极相比，该电极的首次充放电电压平台差为0.12 V，仅为传统电极的约1/3，同时倍率性能也有大幅度提高，而且其传荷电阻可降低至传统电极的1/50。

A novel method to fabricate low tortuosity (as low as 1),ultra-thick hierarchical porous electrode for lithium-ion battery by the extrusion-based three-dimensional (3D) printing technology is presented.Meanwhile,the printable ink is formulated by using the graphene oxide (GO) with a concentration of 80 mg·mL^-1 as viscosity modifier and lithium iron phosphate as electrode active material.The ink has an apparent viscosity as high as 10⁴ Pa·s,and exhibits obvious shear-thinning behavior.It is noted that the ink's storage modulus plateau is as high as 10⁴ Pa·s.These excellent rheological properties are very useful for the printing and curing processes,which ensure precision and integrity of printing structure.It is demonstrated via the electrochemical test that this electrode's initial voltage difference between the charge and discharge plateaus is around 0.12 V,only one third that of the traditional coated electrodes with uniform active materials loading mass of 21 mg·cm^-2.Also,the rate performance of this 3D printed electrode is improved substantially,and its charge transfer resistance can decrease to one fifty that of traditional electrode.

王一博(1985-),女,博士,研究方向为3D打印能源器件,11b325010@hit.edu.com