Garnet-Based All-Ceramic Lithium Battery Enabled by Li(2.985)B(0.005)OCl Solder

Garnet-based bulk-type all-ceramic lithium battery (ACLB) is considered to be highly safe, but its electrochemical performance is severely hindered by the huge cathode/electrolyte interfacial resistance. Here, we demonstrate an in situ coated Li(2.985)B(0.005)OCl as sintering solder, which is uniformly coated on both LiCoO(2) and Li(7)La(3)Zr(2)O(12). With the low melting point (267°C) and high ionic conductivity (6.8 × 10(−5) S cm(−1)), the Li(2.985)B(0.005)OCl solder not only restricts La/Co interdiffusion, but also provides fast Li(+) transportation in the cathode. A low cathode/electrolyte interfacial resistance (386 Ω cm(2)) is realized owing to the densification of the ACLB by hot-press sintering. The strain/stress of the LiCoO(2) is also released by the small elasticity modulus of Li(2.985)B(0.005)OCl, leading to a superior cycling stability. The study sheds light on the design of advanced garnet-based bulk-type ACLB by exploring proper solders with higher ionic conductivity, lower melting point, and smaller elasticity modulus.