The present application provides a negative electrode active material, a process for preparing the same, and a secondary battery, a battery module, a battery pack and an apparatus related the same. The negative electrode active material comprises a core material and a polymer-modified coating layer on at least a part of a surface of the core material, the core material is one or more of a silicon-based negative electrode material and a tin-based negative electrode material, the polymer-modified coating layer comprises sulfur element and carbon element, the sulfur element has a mass percentage of from 0.2% to 4% in the negative electrode active material, the carbon element has a mass percentage of from 0.5% to 4% in the negative electrode active material, and the polymer-modified coating layer comprises a —S—C— bond.

Systems and methods for improved performance of silicon anode containing cells through formation may include a cathode, electrolyte, and silicon containing anode. The battery may be subjected to a formation process comprising one or more cycles of: charging the battery at a 1 C rate to 3.8 volts or greater until a current in the battery reaches C/20, and discharging the battery to 2.5 volts or less. The battery may comprise a lithium ion battery. The electrolyte may comprise a liquid, solid, or gel. The anode may comprise greater than 70% silicon. The battery may be discharged until the current reaches 0.2 C. The battery may be discharged at a 1 C rate or at a 0.2 C rate. The battery may be in a rest period between the charge and discharge.

Systems and methods are provided for carbon additives for direct coating of silicon-dominant anodes. An example composition for use in directly coated anodes may include a silicon-dominated anode active material, a carbon-based binder, and a carbon-based additive, with the composition being configured for low-temperature pyrolysis. The low-temperature pyrolysis may be conducted at <600° C. An anode may be formed using a direct coating process of the composition on a current collector. The anode active material yields silicon constituting between 86% and 97% of weight of the formed anode after pyrolysis. The carbon-based additive yields carbon constituting between 2% and 6% of weight of the formed anode after pyrolysis.

Systems and methods are provided for carbon additives for direct coating of silicon-dominant anodes. An example composition for use in directly coated anodes may include a silicon-dominated anode active material, a carbon-based binder, and a carbon-based additive, with the composition being configured for low-temperature pyrolysis. The low-temperature pyrolysis may be conducted at <600° C. An anode may be formed using a direct coating process of the composition on a current collector. The anode active material yields silicon constituting between 86% and 97% of weight of the formed anode after pyrolysis. The carbon-based additive yields carbon constituting between 2% and 6% of weight of the formed anode after pyrolysis.

An auxiliary electrode includes a conductive layer having a first major surface in an X-Y plane, the conductive layer is electrically conductive and has a first surface area. The auxiliary electrode includes a first carrier ion supply layer and a second carrier ion supply layer, each carrier ion supply layer comprising a material that supplies carrier ions for an electrode of the secondary battery. The first carrier ion supply layer covers a first region of the first major surface of the conductive layer and the second carrier ion supply layer covers a second region of the first major surface of the conductive layer. The first and second regions are separated by a third region, the third region configured to be folded such that the first region and the second region are substantially parallel, and the third region is substantially perpendicular to the first and second regions in the folded configuration.

An auxiliary electrode includes a conductive layer having a first major surface in an X-Y plane, the conductive layer is electrically conductive and has a first surface area. The auxiliary electrode includes a first carrier ion supply layer and a second carrier ion supply layer, each carrier ion supply layer comprising a material that supplies carrier ions for an electrode of the secondary battery. The first carrier ion supply layer covers a first region of the first major surface of the conductive layer and the second carrier ion supply layer covers a second region of the first major surface of the conductive layer. The first and second regions are separated by a third region, the third region configured to be folded such that the first region and the second region are substantially parallel, and the third region is substantially perpendicular to the first and second regions in the folded configuration.

In general, the present disclosure is directed to forming lithium ion battery (LIB) cells with structure and chemistry that achieves formation of a solid electrolyte interphase (SEI) layer that allows for operating in relatively high ambient temperature environments, e.g., up to and exceeding 60° C., while significantly reducing self-discharge amounts, e.g., relative to other LIB cells formed with SEI layers measuring about 1-2 nanometers in thickness. For example, one non-limiting embodiment of the present disclosure enables a self-discharge amount for a LIB cell of 10% or less over a four (4) week period of time when operating at an ambient temperature of 60 degrees Celsius.

In general, the present disclosure is directed to forming lithium ion battery (LIB) cells with structure and chemistry that achieves formation of a solid electrolyte interphase (SEI) layer that allows for operating in relatively high ambient temperature environments, e.g., up to and exceeding 60° C., while significantly reducing self-discharge amounts, e.g., relative to other LIB cells formed with SEI layers measuring about 1-2 nanometers in thickness. For example, one non-limiting embodiment of the present disclosure enables a self-discharge amount for a LIB cell of 10% or less over a four (4) week period of time when operating at an ambient temperature of 60 degrees Celsius.

A negative electrode for a lithium secondary battery, where the negative electrode includes a negative electrode current collector, a negative electrode active material layer, a lithium layer that is positioned between the negative electrode current collector and the negative electrode active material layer, and a primer layer that is positioned between the negative electrode current collector and the lithium layer, and a manufacturing method thereof. This results in a simple method and a negative electrode with high capacity characteristics.

A negative electrode for a lithium secondary battery, where the negative electrode includes a negative electrode current collector, a negative electrode active material layer, a lithium layer that is positioned between the negative electrode current collector and the negative electrode active material layer, and a primer layer that is positioned between the negative electrode current collector and the lithium layer, and a manufacturing method thereof. This results in a simple method and a negative electrode with high capacity characteristics.