High-energy all-solid-state lithium batteries enabled by Co-free LiNiO2 cathodes with robust outside-in structures

A critical current challenge in the development of all-solid-state lithium batteries (ASSLBs) is reducing the cost of fabrication without compromising the performance.  

In this paper* published in Nature Nanotechnology, the team of researchers⁺ report a sulfide ASSLB based on a high-energy, Co-free LiNiO₂ cathode with a robust outside-in structure.  This promising cathode is enabled by the high-pressure O₂ synthesis and subsequent atomic layer deposition of a unique ultrathin Li_xAl_yZn_zO₈ protective layer comprising a Li_xAl_yZn_zO₈ surface coating region and an Al and Zn near-surface doping region.  

This high-quality artificial interphase enhances the structural stability and interfacial dynamics of the cathode as it migrates the contact loss and continuous side reactions at the cathode/solid electrolyte interface.  As a result, the ASSLBs exhibited a high areal capacity (4.65 mAhcm^-2), a high specific cathode capacity (203 mAhg^-1), superior cycling stability (92% capacity retention after 200 cycles) and a good rate capability (93 mAhg^-1at 2C).  This work also offers mechanistic insights into how to break through the limitation of using expensive cathodes (for example, Co-based) and coatings (for example, Nb-, Ta-, La- or Zr -based) while still achieving a high-energy ASSLB performance.

* 'High-energy all-solid-state lithium batteries enabled by Co-free LiNiO2 cathodes with robust outside-in structures'.

⁺  Department of Materials at the University of Oxford, Bar-Ilan University, National Yang Ming Chiao Tung University, Forge Nano Inc, The Hebrew University of Jerusalem, the National Synchrotron Radiaton Research Centre in Hsinchu, Indian Institute of Technology in Delhi, the Max Planck Institute for Chemical Physics of Solids in Dresden,