Secondary battery, and method for manufacturing secondary battery

A method for manufacturing a secondary battery including:

• a wound electrode body formed by winding an elongated positive electrode plate and an elongated negative electrode plate overlapped upon one another via an elongated separator interposed therebetween around an axis;
• and
• electrolyte contained inside the wound electrode body,
• the wound electrode body including a fluid flow restrictor for restricting flow of the electrolyte between inside and outside of the wound electrode body in an axial direction along the axis,
• when a portion where the separator exists in a radial direction of the axis of the wound electrode body is defined as an electrode body central part,
• the fluid flow restrictor is at least one of:
• a one side fluid flow restrictor formed in one axial end portion of one axial end side of the electrode body central part to restrict flow of the electrolyte through the one axial end portion;
• and
• the other side fluid flow restrictor formed in the other axial end portion of the other axial end side of the electrode body central part to restrict flow of the electrolyte through the other axial end portion, and
• the one side fluid flow restrictor and the other side fluid flow restrictor are both formed of a gel-like substance containing the electrolyte and being in a form of a gel,
• wherein the method includes:
• a pre-processed restrictor formation step of forming a pre-processed fluid flow restrictor which is to be subjected to a predetermined flow restricting process to reduce flowability of the electrolyte through the restrictor in the wound electrode body;
• an electrolyte injecting step of injecting the electrolyte into the wound electrode body through the pre-processed fluid flow restrictor after the pre-processed restrictor formation step;
• and
• a restrictor formation step of performing the flow restricting process after the electrolyte injecting step to turn the pre-processed fluid flow restrictor into the fluid flow restrictor,
• the pre-processed restrictor formation step includes at least one of:
• a step of forming a pre-processed one side fluid flow restrictor that is the pre-processed fluid flow restrictor, formed in the one axial end portion of the one axial end side of the electrode body central part;
• and
• a step of forming a pre-processed the other side fluid flow restrictor that is the pre-processed fluid flow restrictor, formed in the other axial end portion of the other axial end side of the electrode body central part,
• the electrolyte injecting step is a step of injecting the electrolyte into the electrode body central part through at least one of the pre-processed one side fluid flow restrictor and the pre-processed the other side fluid flow restrictor, and
• the restrictor formation step includes at least one of:
• a step of turning the pre-processed one side fluid flow restrictor into the one side fluid flow restrictor;
• and
• a step of turning the pre-processed the other side fluid flow restrictor into the other side fluid flow restrictor,
• the pre-processed one side fluid flow restrictor and the pre-processed the other side fluid flow restrictor are both formed of a gelling material that absorbs the electrolyte and turns into a gel when subjected to a heating process, and
• the restrictor formation step is a step of performing the heating process as the flow restricting process to form the gel-like substance from the gelling material.