The present disclosure relates to a lithium secondary battery. Since the lithium secondary battery according to the present disclosure includes a lithium transition metal oxide having a stabilized lattice structure with a hetero-element introduced therein, gas generation during charging and discharging can be suppressed, and improved safety and lifespan can be achieved.

A lithium transition metal composite oxide, comprising a twin crystal structure. The twin crystal structure includes a first crystalline region and a second crystalline region. A grain boundary exists between the first crystalline region and the second crystalline region. The first crystalline region includes a first region located within 20 nm from the grain boundary. The second crystalline region includes a second region located within 20 nm from the grain boundary. An angle between a transition metal layer in the first region and a transition metal layer in the second region is 65? to 80?. By adjusting the angle between the transition metal layer in the first region and the transition metal layer in the second region to fall within 65? to 80?, it can improve stability of the twin crystal structure, and in turn, improve the cycle performance of the electrochemical device at a high voltage.

A solid-state fuel battery comprises an anode, a cathode spaced from the anode, and a solid-state electrolyte disposed between the anode and the cathode. A material of the solid-state electrolyte is a hydrogen-containing transition metal oxide having a structural formula of ABO.sub.xH.sub.y, wherein A is one or more of alkaline earth metal elements and rare-earth metal elements, B is one or more of transition metal elements, x is a numeric value in a range of 1 to 3, and y is a numeric value in a range of 0 to 2.5. A method for making the solid-state electrolyte for the solid-state fuel battery is further provided in the present disclosure.

Various embodiments relate to a method comprising forming a template from a template precursor, wherein the template contains an entrapped ceramic precursor, which can be further processed to form a ceramic solid, such as an oxide ceramic solid. In one embodiment, the template precursor is a hydrogel precursor and the template is a hydrogel template. The hydrogel template can include, for example, agarose, chitosan, alginate or a photo-initiating receptive hydrogel template such as a functionalized poly(ethylene glycol). Various devices, including electrolyte interfaces and energy storage devices, as well as thermoelectric devices are also provided. In one embodiment, the oxide ceramic solid is a cubic garnet having a nominal formula of Li.sub.7La.sub.3Zr.sub.2O.sub.12 (LLZO).

A sodium-containing oxide positive electrode material and a preparation method therefor and use thereof are disclosed. Also disclosed are a positive electrode plate and uses thereof.

A layered lithium metal oxide powder for a cathode material used in a rechargeable battery, with the general formula (1x)[Li.sub.a-bA.sub.b].sub.3a[CO.sub.1-cM.sub.c].sub.3b[O.sub.2-d-eN.sub.e].sub.6c.xLi.sub.3PO.sub.4, with 0.0001x0.05, 0.90a1.10, 0<b+c0.1, 0.1d0.1 and e0.05, wherein A and M are one or more elements including at least one of the group consisting of Mg, Ti and Al; wherein N is either one or more dopants of the group consisting of F, S, N and P; the powder consisting of a core and an ion-conductive electron-insulating surface layer, the core having a layered crystal structure and the surface layer comprising a mixture of elements of the core material, oxides comprising either one or more elements of the group consisting of Mg, Ti and Al; and Li.sub.3PO.sub.4.

Provided is a cobalt precursor for preparing a lithium cobalt oxide of a layered structure which is included in a positive electrode active material, wherein the cobalt precursor is cobalt oxyhydroxide (CoMOOH) doped with, as dopants, magnesium (Mg) and M different from the magnesium.

A NiHf- or NiTi-doped Co.sub.2Y-type ferrite, having a formula of

Ba.sub.n-xSr.sub.xCo.sub.2-yCu.sub.yNi.sub.zHf.sub.zFe.sub.(m-2z)O.sub.22

or

Ba.sub.n-xSr.sub.xCo.sub.2-yCu.sub.yNi.sub.zTi.sub.zFe.sub.(m-2z)O.sub.22

wherein 2?n?2.4. 0?x?1, 0.1?y?1, 0<z?2, and 10?m?13.

A perovskite material represented by Formula 1:
Li.sub.xA.sub.yM.sub.zO.sub.3-?Formula 1 wherein in Formula 1, 0<x?1, 0<y?1, 0<x+y<1, 0<z?1.5, 0???1, A is H, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, or a combination thereof, and M is Ni, Pd, Pb, Fe, Ir, Co, Rh, Mn, Cr, Ru, Re, Sn, V, Ge, W, Zr, Mo, Hf, U, Nb, Th, Ta, Bi, Li, H, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Mg, Al, Si, Sc, Zn, Ga, Ag, Cd, In, Sb, Pt, Au, or a combination thereof.

A sodium-containing oxide positive electrode material and a preparation method therefor and use thereof are disclosed. Also disclosed are a positive electrode plate and uses thereof.