All-solid-state secondary battery
The present disclosure relates to an all-solid-state secondary battery, and more particularly, to an all-solid-state secondary battery including a positive electrode, a negative electrode, and a solid electrolyte layer disposed between the positive electrode and the negative electrode. Here, at least one of the positive electrode and the negative electrode includes a sulfide-based active material, the sulfide-based active material has a particle size of about 50 nm to about 5 μm, and the sulfide-based active material has a grain size of about 1 nm to about 10 nm.
1 . An all-solid-state secondary battery comprising:
a positive electrode;
a negative electrode comprising a lithium metal; and
a solid electrolyte layer disposed between the positive electrode and the negative electrode;
wherein the positive electrode comprises a sulfide-based active material, the sulfide-based active material has a particle size of about 50 nm to about 5 μm,
the sulfide-based active material has amorphousness sufficiently high to have a grain size of about 1 nm to about 10 nm,
the sulfide-based active material includes a titanium disulfide, and
the solid electrolyte layer includes a sulfide-based material, or an oxide-based material, or both.
2 . The all-solid-state secondary battery of claim 1 , wherein the sulfide-based active material consists of the titanium disulfide.
3 . The all-solid-state secondary battery of claim 1 , wherein at least one of the positive electrode or the negative electrode comprises a polymeric binder, and
a concentration of the polymeric binder is 0.01 wt % to 5 wt %.
4 . The all-solid-state secondary battery of claim 3 , wherein the polymeric binder comprises at least one of polytetrafluoroethylene, polyvinylidene fluoride (PVdF), poly(ethylene oxide), polyacrylonitrile, hydroxypropyl cellulose, carboxymethyl cellulose, styrene-butadiene, nitrile-butadiene rubber, polyacrylate, or polyacrylic acid.
5 . The all-solid-state secondary battery of claim 1 , wherein at least one of the positive electrode or the negative electrode comprises an electro-conducting agent, and a concentration of the electro-conducting agent is 0.01 wt % to 5 wt %.
6 . The all-solid-state secondary battery of claim 5 , wherein the electro-conducting agent comprises at least one of graphite, hard/soft carbon, carbon fibers, carbon nanotubes, linear carbon, carbon black, acetylene black, or ketjen black.
7 . The all-solid-state secondary battery of claim 1 , wherein each of the positive electrode and the negative electrode has a porosity greater than 0 and equal to or less than 15%.
8 . The all-solid-state secondary battery of claim 1 , wherein the sulfide-material of the solid electrolyte layer includes one selected from the group consisting of Li 4-x Ge 1-x P x S 4 (LGPS), Li 3 PS 4 glass-ceramic, Li 7 P 3 S 11 glass-ceramic (LPS), Li 4 SnS 4 , and Li 6 PS 5 X (X=I, Br or Cl).
9 . The all-solid-state secondary battery of claim 1 , wherein the oxide-based material of the solid electrolyte layer includes one selected from the group consisting of Li 3x La 2/3-x TiO 3 (LLTO), Li i+x Ti 2-x M x (PO 4 ) 3 (M=AI, Ga, In or Sc), and Li 7 La 3 Zr 2 O 12 (LLZO).