From active materials to solid electrolytes for Na-based batteries (12/03/26)
Speaker and Affliation:
Prof. Matteo Bianchini
Bavarian Center for Battery Technology, BayBatt, University of Bayreuth, Germany
When?
12th March, 2026 (Thursday), 04.00 PM (India Standard Time)
Where
KI Vasu Auditorium, Dept. of Materials Engineering, IISc, Bangalore
Abstract:
In the Bianchini group at BayBatt, we investigate materials for Na-based batteries within the ERC project 4SBATT (Sustainable Solid-State Sodium Batteries) and the national SIB:DE consortium, which targets sodium-ion batteries produced in Germany. This presentation summarizes our recent advances on positive and negative electrode materials as well as halide solid electrolytes. For positive electrodes, we focus on P2-type layered oxides (NaxTMO2) that oSer low Na+ -diSusion barriers but suSer from limited sodium content and irreversible P2–O2 transitions at high voltage1,2,3 . We address these issues via inactive-element doping and studied a series of Li-doped P2 materials, Na5/6LiyNi5/12–3y/2Mn7/12+y/2O2. Using temperature-resolved in situ XRD, we uncovered a previously unreported P3–P2 core-shell reaction during synthesis4,5. Operando XRD/XAS reveal that Li substitution suppresses high-voltage phase transitions and tunes O-redox. A composition with y ≈ 0.1 provides the best balance between cycling stability, rate capability, and structural robustness. We also assessed the influence of particle morphology and surface area on performance. For negative electrodes, to overcome the limited volumetric capacity of hard carbon (HC), we design HC/Sn composites using tin as a high-capacity and high-density secondary component6 . HC/Sn materials are produced by spray drying and characterized by spectroscopy, scattering (including SAXS), and electrochemistry. Operando XRD confirms expected phase evolution during sodiation, while recent work highlights unexpected features in Sn electrochemistry. Our composites demonstrate improved gravimetric and volumetric performance relative to HC, making them promising anode candidates for next-generation Na-ion batteries7 . Finally, in solid electrolytes, we explore sodium metal chlorides, valued for mechanical processability and stability but limited by modest room-temperature ionic conductivity. Through cation and anion substitution in NaAlCl4- and Na2ZnCl4-based systems, we optimize Na+ transport and electrochemical stability8 . Aliovalent Al 3+ or Zn2+ doping enhances conductivity, while Ga3+ isovalent substitution broadens stability windows9 . These findings provide design guidelines for halide solid electrolytes and identify promising catholytes for solid-state Na batteries.
Speaker Bio :
Matteo Bianchini studied physics engineering at Politecnico di Milano and obtained his PhD in Solid State Chemistry in 2015 with Prof. Masquelier, Dr. Croguennec and Dr. Suard in France (LRCS, ICMCB and ILL). He was a postdoctoral researcher in the group of Prof. Ceder at LBNL, working on the design, synthesis, and characterization of materials for Na- and K-ion batteries. He then became a postdoctoral researcher at BELLA-KIT (Prof. Janek), where he investigated Ni-rich cathode materials for Li-ion batteries, prior to joining BASF as a lab team leader to co-supervise the BELLA lab. In 2021 Matteo obtained the chair of Inorganic Active Materials for Electrochemical Energy Storage at the University of Bayreuth, part of the Bavarian Center for Battery Technology, where his group investigates and develops electrode materials, synthetic methods and analytical tools for the next generation of batteries. In Bayreuth, Matteo is the program moderator of the master “Battery Materials and Technology” and is member of the board of directors of BayBatt. As of 2025, he is also co-director of the ALISTORE European research institute.