Authors: Hongli Wan, Liangting Cai, Fudong Han, Jean Pierre Mwizerwa, Chunsheng Wang, Xiayin Yao
Published: 2019-11-14
Source: Full article
AbstractHigh and balanced electronic and ionic transportation networks with nanoscale distribution in solid‐state cathodes are crucial to realize high‐performance all‐solid‐state lithium batteries. Using Cu2SnS3 as a model active material, such a kind of solid‐state Cu2SnS3@graphene‐Li7P3S11 nanocomposite cathodes are synthesized, where 5–10 nm Cu2SnS3 nanoparticles homogenously anchor on the graphene nanosheets, while the Li7P3S11 electrolytes uniformly coat on the surface of Cu2SnS3@graphene composite forming nanoscaled electron/ion transportation networks. The large amount of nanoscaled triple‐phase boundary in cathode ensures high power density due to high ionic/electronic conductions and long cycle life due to uniform and reduced volume change of nano‐Cu2SnS3. The Cu2SnS3@graphene‐Li7P3S11 cathode layer with 2.0 mg cm−2 loading in all‐solid‐state lithium batteries demonstrates a high reversible discharge specific capacity of 813.2 mAh g−1 at 100 mA g−1 and retains 732.0 mAh g−1 after 60 cycles, corresponding to a high energy density of 410.4 Wh kg−1 based on the total mass of Cu2SnS3@graphene‐Li7P3S11 composite based cathode. Moreover, it exhibits excellent rate capability and high‐rate cycling stability, showing reversible capacity of 363.5 mAh g−1 at 500 mA g−1 after 200 cycles. The study provides a new insight into constructing both electronic and ionic conduction networks for all‐solid‐state lithium batteries.