Provided are electrochemically active secondary particles that provide excellent capacity and improved cycle life. The particles are characterized by selectively enriched grain boundaries where the grain boundaries are enriched with Al and Co. The enrichment with Al reduces impedance generation during cycling thereby improving capacity and cycle life. Also provided are methods of forming electrochemically active materials, as well as electrodes and electrochemical cells employing the secondary particles.

Provided are electrochemically active secondary particles that provide excellent capacity and improved cycle life. The particles are characterized by selectively enriched grain boundaries where the grain boundaries are enriched with Al and Co. The enrichment with Al reduces impedance generation during cycling thereby improving capacity and cycle life. Also provided are methods of forming electrochemically active materials, as well as electrodes and electrochemical cells employing the secondary particles.

A positive active material for a rechargeable lithium battery includes a compound represented by Chemical Formula 1, Li.sub.aNi.sub.xCo.sub.yMe.sub.zM.sup.1.sub.kM.sup.2.sub.pO.sub.2 wherein, 0.9a1.1, 0.7x0.93, 0<y0.3, 0<z0.3, 0.001k0.006, 0.001p0.005, x+y+z+k+p=1, Me is Mn or Al, M.sup.1 is a divalent element, and M.sup.2 is a tetravalent element.

A positive electrode active material for non-aqueous electrolyte secondary battery with improved cycle characteristics and high temperature storage characteristics, without impairing an advantage of high capacity which lithium nickel composite oxide inherently possesses. The positive electrode active material for non-aqueous electrolyte secondary battery includes lithium nickel composite oxide represented by a general formula (1): Li.sub.1+uNi.sub.1xyzCo.sub.xMn.sub.yMg.sub.zO.sub.2 (However, u, x, y and z in the formula satisfies 0.015u0.030, 0.05x0.20, 0.01y0.10, 0.01z0.05, 0.10x+y+z0.25.), and wherein crystallite diameter is 100 nm to 130 nm. In addition, the positive electrode active material for non-aqueous electrolyte secondary battery is produced at least by an oxidation roasting step, a mixing step, and a calcining step.

Provided are electrochemically active secondary particles that provide excellent capacity and improved cycle life. The particles are characterized by selectively enriched grain boundaries where the grain boundaries are enriched with Al and Co. The enrichment with Al reduces impedance generation during cycling thereby improving capacity and cycle life. Also provided are methods of forming electrochemically active materials, as well as electrodes and electrochemical cells employing the secondary particles.

The present invention provides a positive electrode active material for a secondary battery, the positive electrode active material including a lithium composite metal oxide particle represented by Formula 1 below, and a secondary battery including the same.
Li.sub.aNi.sub.1xyCo.sub.xM1.sub.yM2.sub.zM3.sub.wO.sub.2[Formula 1] In Formula 1, M1 is a metal element whose surface energy (E.sub.surf) calculated by Equation 1 below is 0.5 eV or higher, M2 is a metal element whose surface energy (E.sub.surf) calculated by Equation 1 below is 1.5 eV or higher and less than 0.5 eV, M3 is a metal element whose surface energy (E.sub.surf) calculated by Equation 1 below is less than 1.5 eV, and 1.0a1.5, 0<x0.5, 0<z0.05, 0.002w0.1, 0<x+y0.7. $\begin{array}{c}\begin{array}{c}{E}_{\mathrm{surf}}=E_{\mathrm{surf}2}-E_{\mathrm{surf}1}\\ =(E_{\mathrm{slab}}\end{array}\end{array}$

A positive electrode active material for a lithium secondary cell, having a layered structure and comprising at least nickel, cobalt and manganese, the positive electrode active material satisfying requirements (1), (2) and (3) below: (1) a composition represented by a composition formula: Li[Li.sub.x(Ni.sub.Co.sub.Mn.sub.M.sub.).sub.1-x]O.sub.2, wherein 0x0.10, 0.30<0.34, 0.30<0.34, 0.32<0.40, 00.10, <, +++=1, M represents at least one metal selected from the group consisting of Fe, Cu, Ti, Mg, Al, W, Zn, Sn, Zr, Ga and V; (2) a secondary particle diameter of 2 m or more and 10 m or less; and (3) a maximum peak value in a pore diameter range of 90 nm to 150 nm in a pore diameter distribution determined by mercury porosimetry.

Vessels selected from crucibles, pans, open cups and saggars essentially comprising of two components, from which (A) one component being a ceramic matrix composite, and (B) the second component being from metal or alloy, and wherein component (A) is the inner one.

Provided are electrochemically active secondary particles that provide excellent capacity and improved cycle life. The particles are characterized by selectively enriched grain boundaries where the grain boundaries are enriched with Al and Co. The enrichment with Al reduces impedance generation during cycling thereby improving capacity and cycle life. Also provided are methods of forming electrochemically active materials, as well as electrodes and electrochemical cells employing the secondary particles.

Provided are electrochemical cells that include as a cathode active material within the cathode of the cell secondary particles that provide excellent capacity and improved cycle life. The particles are characterized by grain boundaries between adjacent crystallites of the plurality of crystallites and comprising a second composition having a layered -NaFeO.sub.2-type structure, a cubic structure, a spinel structure, or a combination thereof, wherein the electrochemically active cathode active material has an initial discharge capacity of 180 mAh/g or greater; and wherein the electrochemical cell has an impedance growth at 4.2V less than 50% for greater than 100 cycles at 45 C.