Among the 3D-printing technologies, fused deposition modeling (FDM) represents a promising route to enable direct incorporation of the battery within the final 3D object. Here, the preparation and characterization of lithium iron phosphate/polylactic acid (LFP/PLA) and SiO₂/PLA 3D-printable filaments, specifically conceived respectively as positive electrode and separator in a lithium-ion battery is reported. By means of plasticizer addition, the active material loading within the positive electrode is raised as high as possible (up to 52 wt.%) while still providing enough flexibility to the filament to be printed. A thorough analysis is performed to determine the thermal, electrical and electrochemical effect of carbon black as conductive additive in the positive electrode and the electrolyte uptake impact of ceramic additives in the separator. Considering both optimized filaments composition and using our previously reported graphite/PLA filament for the negative electrode, assembled and “printed in one-shot” complete LFP/Graphite battery cells are 3D-printed and characterized. Taking advantage of the new design capabilities conferred by 3D-printing, separator patterns and infill density are discussed with a view to enhance the liquid electrolyte impregnation and avoid short-circuits.

Additive manufacturing technologies open the way to the direct-integration of electronics and solid-state battery within the final 3D object. Here, a 3D printable polyethylene oxide/lithium bis(trifluoromethanesulfonyl)imide (PEO/LiTFSI) filament (2.18 × 10⁻³ S cm⁻¹ at 90 °C) optimized to be used as solid polymer electrolyte in a lithium-ion battery is produced to feed a fused deposition modeling (FDM) 3D-printer. Due to its relatively poor mechanical properties compared to classical polymer filament such as polylactic acid (PLA), deep modifications of the 3D-printer were implemented in order to facilitate its printability. The solid polymer electrolyte thermal, structural, morphological, mechanical and electrical characterization is reported. Interestingly, using three different electrochemical impedance spectroscopy sample holders (lateral, sandwich and interdigitated-comb), we demonstrate that conductivity values differs for a same sample, highlighting the PEO chains orientation effect on the conductivity measurements.

High-resolution additive manufacturing offers access to the production of intricate architectures with small features that can revolutionize the fabrication of next-generation batteries. Relegated to two-dimensional sheets, commercial lithium-ion batteries consist of stacked leaflets, which are manufactured in restricted stacked or rolled geometries. By leveraging the most recent advancements of vat photopolymerization (VPP), the next-generation of shape-conformable three-dimensional batteries can be co-designed with known application requirements and provide enhanced safety and power performance based on reduced weight and dead volume. Herein, an overview of the state of the art with perspectives towards the development of electroactive photo-polymerizable resins for the direct fabrication of complete multi-material three-dimensional batteries is presented. Different approaches are described, including the formulation of composite resin through the introduction of solid electroactive particles, soluble components or metal precursors. Finally, the impact of the thermal post-processing steps on the resulting electrochemical properties of the VPP printed battery component or device is thoroughly discussed. This study paves the way towards the manufacturing of a complete high-resolution shape conformable 3D battery via VPP with enhanced power density.

In this paper, the development of an environmentally-friendly lithium-terephtalate/polylactic acid (Li₂TP/PLA) composite filament, for its use, once 3D-printed via Fused Deposition Modeling (FDM), as negative electrode of a lithium-ion battery is reported. Solvent-free formulation of the 3D-printable filament is achieved through the direct introduction of synthesized Li₂TP particles and PLA polymer powder within an extruder. Printability is improved through the incorporation of poly(ethylene glycol) dimethyl ether average M_n∼500 (PEGDME500) as plasticizer, while electrical performances are enhanced through the introduction of carbon black (CB). Thermal, electrical, morphological, electrochemical and printability characteristics are discussed thoroughly. By taking advantage of the 3D-printing slicer software capabilities, an innovative route is proposed to improve the liquid electrolyte impregnation within the 3D-printed electrodes.

Among the various additive manufacturing processes, material extrusion techniques recently emerged as an encouraging option in order to 3D-print lithium-ion battery components. In this work, an overview of the recent advances and progress on the ink material extrusion, known as liquid deposition modeling (LDM), as well as the thermoplastic material extrusion process, known originally as the trademark Fused Deposition Modeling (FDM), is discussed. Representing a promising route to achieve complete lithium-ion batteries in a single print without the necessity to perform any post-processes, a particular consideration is devoted to the FDM process. Trends, prospects as well as an exhaustive list of the parameters still requiring further investigations are provided, thus paving the way towards the next generation of FDM 3D-printed lithium-ion batteries.