All-Solid-State Lithium Battery with LiNiO₂ Cathode

We report an all-solid-state lithium battery (ASSLB) based on a sulfide solid electrolyte and a LiNiO₂ cathode. The latter is prepared with an outside-in structure.^[1-3] The cathode is enabled by a high-pressure O₂ synthesis and subsequent atomic layer deposition of an ultrathin Li_<i>x</i>Al<i>_y</i>Zn<i>_z</i>O<i>_δ</i> (LAZO) protective layer comprising a LAZO surface coating and an Al and Zn near-surface doping region. This interphase enhances the structural stability and interfacial dynamics of the cathode as it mitigates continuous side reactions at the cathode/solid electrolyte interface. Our ASSLBs exhibit a high areal capacity of 4.65 mAh/cm², a high specific cathode capacity of 203 mAh/g, cycling stability corresponding to 92% capacity retention after 200 cycles and a rate capability of 93 mAh/g.<br/><br/><b>References</b><br/>1. Janek, J. & Zeier, W. G. Challenges in speeding up solid-state battery development. Nat. Energy 8, 230–240 (2023).<br/>2. Wang, L. et al. High-energy all-solid-state lithium batteries enabled by Co-free LiNiO₂ cathodes with robust outside-in structures. Nat. Nanotechnol. 19, 208–218 (2024).<br/>3. Gao, X. et al. Solid-state lithium battery cathodes operating at low pressures. Joule 6, 636–646 (2022).