A prussian blue analog having a core-shell structure, which has a core and a cladding layer that dads the core, wherein

the chemical formula of the core is the following Formula 1,

Na.sub.xP[R(CN).sub.6].sub.δ.zH.sub.2O and the chemical formula of the cladding layer is the following Formula 2, A.sub.yL[M(CN).sub.6].sub.α.wH.sub.2O is described. The prussian blue analog has good storage stability, and thus can greatly reduce the manufacturing cost at the subsequent battery cell level. A method for preparing the prussian blue analog having a core-shell structure, as well as a sodium-ion secondary battery, a battery module, a battery pack and a powered device comprising the same are described.

A prussian blue analog having a core-shell structure, which has a core and a cladding layer that dads the core, wherein

the chemical formula of the core is the following Formula 1,

Na.sub.xP[R(CN).sub.6].sub.δ.zH.sub.2O and the chemical formula of the cladding layer is the following Formula 2, A.sub.yL[M(CN).sub.6].sub.α.wH.sub.2O is described. The prussian blue analog has good storage stability, and thus can greatly reduce the manufacturing cost at the subsequent battery cell level. A method for preparing the prussian blue analog having a core-shell structure, as well as a sodium-ion secondary battery, a battery module, a battery pack and a powered device comprising the same are described.

Separator systems for electrochemical systems providing electronic, mechanical and chemical properties useful for applications including electrochemical storage and conversion. Separator systems include structural, physical and electrostatic attributes useful for managing and controlling dendrite formation and for improving the cycle life and rate capability of electrochemical cells including silicon anode based batteries, air cathode based batteries, redox flow batteries, solid electrolyte based systems, fuel cells, flow batteries and semisolid batteries. Separators include multilayer, porous geometries supporting excellent ion transport properties, providing a barrier to prevent dendrite initiated mechanical failure, shorting or thermal runaway, or providing improved electrode conductivity and improved electric field uniformity, as well as composite solid electrolytes with supporting mesh or fiber systems providing solid electrolyte hardness and safety with supporting mesh or fiber toughness and long life required for thin solid electrolytes without fabrication pinholes or operationally created cracks.

Separator systems for electrochemical systems providing electronic, mechanical and chemical properties useful for applications including electrochemical storage and conversion. Separator systems include structural, physical and electrostatic attributes useful for managing and controlling dendrite formation and for improving the cycle life and rate capability of electrochemical cells including silicon anode based batteries, air cathode based batteries, redox flow batteries, solid electrolyte based systems, fuel cells, flow batteries and semisolid batteries. Separators include multilayer, porous geometries supporting excellent ion transport properties, providing a barrier to prevent dendrite initiated mechanical failure, shorting or thermal runaway, or providing improved electrode conductivity and improved electric field uniformity, as well as composite solid electrolytes with supporting mesh or fiber systems providing solid electrolyte hardness and safety with supporting mesh or fiber toughness and long life required for thin solid electrolytes without fabrication pinholes or operationally created cracks.

A lithium-sulfur battery cathode including conductive porous carbon particles vacuum infused with sulfur and a conductive collector substrate to which the sulfur infused porous carbon particles are deposited. The sulfur infused carbon particles are encapsulated by an encapsulation polymer, the encapsulation polymer having ionic conductivity, electronic conductivity, polysulfide affinity, or combinations thereof. A lithium-sulfur battery including the lithium-sulfur battery cathode, a lithium anode and an electrolyte disposed between the sulfur cathode and the lithium anode is also provided. Methods of producing the sulfur cathode for use in a lithium-sulfur battery by a hybrid vacuum-and-melt method are also provided.

The present disclosure provides methods of compensation for capacity loss resulting from cycle-induced lithium consumption in an electrochemical cell including at least one electrode. Such methods may include adding a lithiation additive to the at least one electrode so as to create a lithium source. The lithium source compensates for cycle-induced lithiation loss such that the electrochemical cell having the lithiation additive experiences total capacity losses of less than or equal to about 5% of an initial capacity prior to cycling of lithium. The lithiation additive includes a lithium silicate represented by the formula Li.sub.uH.sub.r, where H.sub.r=Li.sub.y-uSiO.sub.z and where 0≤y≤3.75 and 0≤z≤2 and u is a useable portion of y, 0≤u≤y. The lithium source may include $\frac{z}{4}L{i}_4\mathrm{Si}{O}_4$
and Li.sub.mSi, where 0≤m≤4.4.

The present disclosure provides methods of compensation for capacity loss resulting from cycle-induced lithium consumption in an electrochemical cell including at least one electrode. Such methods may include adding a lithiation additive to the at least one electrode so as to create a lithium source. The lithium source compensates for cycle-induced lithiation loss such that the electrochemical cell having the lithiation additive experiences total capacity losses of less than or equal to about 5% of an initial capacity prior to cycling of lithium. The lithiation additive includes a lithium silicate represented by the formula Li.sub.uH.sub.r, where H.sub.r=Li.sub.y-uSiO.sub.z and where 0≤y≤3.75 and 0≤z≤2 and u is a useable portion of y, 0≤u≤y. The lithium source may include $\frac{z}{4}L{i}_4\mathrm{Si}{O}_4$
and Li.sub.mSi, where 0≤m≤4.4.

A method of forming a sulfur-based cathode material includes: 1) providing a sulfur-based nanostructure; 2) coating the nanostructure with an encapsulating material to form a shell surrounding the nanostructure; and 3) removing a portion of the nanostructure through the shell to form a void within the shell, with a remaining portion of the nanostructure disposed within the shell.

A method of forming a sulfur-based cathode material includes: 1) providing a sulfur-based nanostructure; 2) coating the nanostructure with an encapsulating material to form a shell surrounding the nanostructure; and 3) removing a portion of the nanostructure through the shell to form a void within the shell, with a remaining portion of the nanostructure disposed within the shell.

A method of forming a crystalline cathode layer of a solid-state battery on a substrate, the method including generating a plasma remote from one or more sputter targets for forming the cathode layer, generating sputtered material from the target or targets using the plasma, and depositing the sputtered material on the substrate, thereby forming the crystalline cathode layer.