High mass loading additive-free LiFePO4 cathodes with 500 μm thickness for high areal capacity Li-ion batteries

Abstract

We report the preparation of thick ceramic electrodes of the olivine LiFePO (LFP) with high mass loading is reported. These electrodes are preparated by means of Powder Extrusion Moulding (PEM), which is a technology easily scalable and cheap. These LFP cathodes are additive-free (neither binder nor extra carbon black) with ~0.5 mm thickness, allowing to develop very high areal capacity (13.7 mA h cm -2 ). By means of a strict control of sintering process, the carbon coating of the commercial LFP powder remains and the decomposition of the active material is prevented. The optimized self-supported LFP cathode presents good cyclability over 20 cycles at C/10 with no capacity loss. The good electrochemical performance of these novel LFP thick electrodes and their non-flammability make them interesting candidates for both mobile and stationary applications.

Challenges in Solvent-Free Methods for Manufacturing Electrodes and Electrolytes for Lithium-Based Batteries

“…This study proves that porous electrodes can be made by solvent-free extrusion even if the particle content is high. A similar process (Figure 8) was recently used by De la Torre-Gamarra et al (2020) to make binder-free self-supported thick LFP-electrodes of approximately 500 microns [91]. In this study, the sacrificial binder (PP, paraffin wax and SA) and the powders (LFP and conductive carbons) were first mixed at 180 °C for 40 min.…”

Tortuosity Modulation toward High‐Energy and High‐Power Lithium Metal Batteries

“…Currently, the layered cathode materials for lithium batteries include LiNi 0.8 Co 0.1 Mn 0.1 O 2 , [78][79][80] LiMnO 2 , [81][82] LiCoO 2 , [83][84][85] and LiFePO 4 [86][87][88][89][90] (LFP), which are ground with acetylene black and polymer binders, and coated on the current collector to prepare the cathodes. The randomly assembled cathodes generate high-tortuous and discontinuous conductive pathways for ions and electrons, resulting in low-rate capabilities.…”

Dry electrode technology, the rising star in solid-state battery industrialization

“…20 On the other hand, the extrusion strategy can fabricate the electrode with high contents of active materials (>90 wt %) with an extremely high mass loading of >5 mAh/cm 2 or even 10 mAh/cm 2 . [61][62][63] (4) 3D printing 3D printing is a developing concept to fabricate 3D materials with special morphologies that has also been applied to battery areas. 64,65 Dry 3D printing applies the mechanism of fused deposition modeling (FDM) without the aid of solvent.…”

“…The thick electrodes of high mass loading (>4 mAh/cm 2 , >20 mg/cm 2 , >200 mm) fabricated by slurry casting suffer from fragility and powder drops due to the severe binder gradient during solvent evaporation. 40 Without the binder gradient, the DBE can realize extremely high mass loading electrodes of 4 mAh/cm 2 (27 mg/cm 2 ) 91 or 6.8 mAh/cm 2 (by Maxwell-type DBE) 49 and can even reach >13 mAh/cm 2 (100 mg/ cm 2 , 500 mm by melting extrusion) 62,63 with considerable adhesion.…”