The present invention relates to a lithium secondary battery, and in particular, to a lithium secondary battery including a positive electrode, a negative electrode, and a separator and an electrolyte interposed between the positive electrode and the negative electrode, wherein a gel polymer electrolyte is included between the negative electrode and the separator, and a liquid electrolyte is included between the positive electrode and the separator. The lithium secondary battery according to the present invention uses a different electrolyte in each of a positive electrode and a negative electrode improving stability and performance of the electrodes, and as a result, performance and a life time of the lithium secondary battery may be enhanced.

A lithium secondary battery which is made of an anode-free battery and includes lithium metal formed on a negative electrode current collector by charging. The lithium secondary battery includes the lithium metal formed on the negative electrode current collector in a state of being shielded from the atmosphere, so that the generation of a surface oxide layer (native layer) formed on the negative electrode according to the prior art does not occur fundamentally, thereby preventing the deterioration of the efficiency and life characteristics of the battery.

In a flow battery according to one aspect of the present disclosure, a first liquid does not include an undesired compound. The flow battery satisfies requirement (i), (ii), (iii) or (iv). (i) An anode active material 14 includes graphite, and the first liquid has an equilibrium potential of not more than 0.15 V vs. Li/Li.sup.+. (ii) An anode active material includes aluminum, and the first liquid has an equilibrium potential of not more than 0.18 V vs. Li/Li.sup.+. (iii) An anode active material includes tin, and the first liquid has an equilibrium potential of not more than 0.25 V vs. Li/Li.sup.+. (iv) An anode active material includes silicon, and the first liquid has an equilibrium potential of not more than 0.25 V vs. Li/Li.sup.+.

In a flow battery according to one aspect of the present disclosure, a first liquid does not include an undesired compound. The flow battery satisfies requirement (i), (ii), (iii) or (iv). (i) An anode active material 14 includes graphite, and the first liquid has an equilibrium potential of not more than 0.15 V vs. Li/Li.sup.+. (ii) An anode active material includes aluminum, and the first liquid has an equilibrium potential of not more than 0.18 V vs. Li/Li.sup.+. (iii) An anode active material includes tin, and the first liquid has an equilibrium potential of not more than 0.25 V vs. Li/Li.sup.+. (iv) An anode active material includes silicon, and the first liquid has an equilibrium potential of not more than 0.25 V vs. Li/Li.sup.+.

A solid-state battery cell includes a cathode comprising a cathode glass fiber scaffold impregnated with cathode active material, an anode comprising an anode glass fiber scaffold impregnated with lithium metal or a lithium metal alloy, and a first electrolyte layer comprising an electrolyte glass fiber scaffold impregnated with a first solid-state electrolyte, the electrolyte layer positioned between the cathode and the anode and the electrolyte glass fiber scaffold extending throughout the first electrolyte layer.

A thin-film lithium ion battery includes a negative electrode layer, a positive electrode layer, an electrolyte layer disposed between the positive and negative electrode layers, and a lithium layer with lithium pillars extending therefrom formed in the negative electrode layer adjoining the electrolyte layer.

A silicon-based electrode forms an interface with a layer pair being: 1. a thin, semi-dielectric layer made of a lithium (Li) compound, e.g. lithium fluoride, LiF, disposed on and adheres to the electrode surface of the silicon-based electrode and 2. an molten-ion conductive layer of a lithium containing salt (lithium salt layer) disposed on the semi-dielectric layer. One or more device layers can be disposed on the layer pair to make devices such as energy storage devices, like batteries. The interface has a low resistivity that reduces the energy losses and generated heat of the devices.

A solid-state ion conductor includes a compound of Formula 1:
Li.sub.3a+b−(c*N)N.sub.aCl.sub.bX.sub.c  Formula 1
wherein, in Formula 1, X is an anion having an average oxidation state of n and is −3≤n≤−1, and is at least one of Br, I, F, O, S, or P; and 1≤a≤4, 1≤b≤3, 0<c≤3, and 4.8≤(a+b+c)≤5.2.

An alkali polysulphide flow battery, components, systems and compositions for use with an alkali polysulphide flow battery and a method of manufacturing and operating a flow battery system are provided. An ion-selective separator composition for a battery having an anode and an alkali metal sulfide or polysulfide cathode is provided. The separator composition includes an alkali metal ion conducting separator film for separating the anode and the cathode, a carbon layer disposed to a cathode side of the film and an alkali metal ion conductor layer disposed to an anode side of the carbon layer.

An alkali polysulphide flow battery, components, systems and compositions for use with an alkali polysulphide flow battery and a method of manufacturing and operating a flow battery system are provided. An ion-selective separator composition for a battery having an anode and an alkali metal sulfide or polysulfide cathode is provided. The separator composition includes an alkali metal ion conducting separator film for separating the anode and the cathode, a carbon layer disposed to a cathode side of the film and an alkali metal ion conductor layer disposed to an anode side of the carbon layer.