In the search for better performing battery materials, researchers have increasingly ventured into complex composition spaces, including numerous pseudo-quaternaries, with numerous further substitutions being either explored experimentally or proposed based on computation. Given the vast composition spaces that need exploring, experimental combinatorial science can play an important role in accelerating the development of advanced battery materials and is arguably the best means to obtain a sufficiently large data set to truly bring a high degree of precision to advanced computational techniques such as machine-learning. Herein, we present a robust high-throughput synthesis platform that is currently being used in the McCalla lab at McGill University to study Li-ion cathodes, anodes and solid electrolytes, as well as Na-ion cathodes. The synthesis methods used are presented in detail, as are the high-throughput characterization techniques we utilize regularly (X-ray diffraction, electrochemical testing and electrochemical impedance spectroscopy). We quantitatively determine the high precision and reproducibility achieved by this combinatorial system and also demonstrate its versatility by presenting for the first time combinatorial data for two high-power anodes for Li-ion batteries (TiNb2O7 and W3-Nb14O44) as well as solid state electrolyte Li7La3Zr2O12. Our methods reproduce accurately the results from the literature for bulk samples, indicating that the high-throughput methodology utilizing small mg-scale samples scale up extremely well to the larger sample sizes typically used in both the literature and industry. The throughput of this combinatorial infrastructure has a current limit of 896 XRD patterns and 896 EIS patterns a week, and 448 cyclic voltammograms running simultaneously.

High voltage cathodes are attractive for high energy density Li‐ion batteries. However, candidates such as LiCoPO4 have presented numerous challenges stemming from poor electronic/ionic conductivities such that typical solutions involving nanosizing result in extremely poor cycling performance. Here, high‐throughput methods are applied to develop near‐micron sized carbon‐coated LiCoPO4 with improved energy density and capacity retention. In total, 1300 materials with 46 different substituents are synthesized and characterized. A number of substituents show greatly improved capacity (e.g., 160 mAh g−1 for 1% indium (In) substitution vs 95 mAh g−1 for the pristine). However, co‐doping is required to improve extended cycling. Li1–3xCo1–2xInxMoxPO4 is found to be particularly effective with dramatically improved cycling (as high as 100% after 10 cycles, vs ≈50% in unsubstituted). While In improves the electronic conductivity of the carbon‐coated materials, molybdenum (Mo) co‐doping gives larger particles. DFT calculations show that Mo impedes the formation of Li/Co antisite defects.

Na-ion batteries are considered to be environmentally favourable alternatives to Li-ion batteries, particularly in the extremely large-scale application of grid storage, given the abundance of Na. However, to date, the...

Na–Mn–O cathodes are very promising for sodium-ion batteries but suffer major setbacks related to long-term cycling and stability in air. With our high-throughput approach, a systematic investigation of 52 different dopants of Na0.66MnO2 from across the periodic table was performed. The chemical composition of Na0.66Mn0.9M0.1O2+δ (M = dopant) is utilized to unravel the impact of dopants on the layered structure and investigate how different dopants influence the battery performance and air and moisture stability. A broad range of doping was possible, with 20 different dopants fully integrating into the Na–Mn–O structures, including several previously unstudied dopants (Si, Sc, Ga, Rb, Rh, Cs, Re, and Tl). This yields high-interest novel cathodes, including a Rb-doped sample with a high specific capacity of 200 mA h g–1, as well as Mo- and Nb-doped samples with excellent capacity retentions of 98% and 100%, respectively, after 10 cycles compared to 92% in undoped Na0.66MnO2. The air and moisture stability of the cathode material is studied systematically, and a number of compositions show ultrahigh stability in air. This systematic approach provides a rapid overview of the benefits of individual dopants and also provides an excellent opportunity to elucidate trends across the periodic table. Significantly, we find that the presence of reversible anionic redox (absent in the undoped samples) correlates remarkably well to the bond valence sum of the dopants, implying that dopants can be used to tune the polarity of M–O bonds and encourage anionic redox behavior. Such “speed dating” reveals fundamental chemical insights and guides further design.

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