Positive electrode for lithium-ion secondary battery, and lithium-ion secondary battery

A lithium-ion secondary battery comprising:

• a positive electrode layer comprising a positive electrode particle comprising
• a positive active material comprising a lithium salt, and
• a coating layer comprising an amorphous carbonaceous layer on a surface of the positive active material;
• a negative electrode layer comprising a negative active material;
• and
• a sulfide solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, wherein the sulfide solid electrolyte layer comprises a sulfide solid electrolyte comprising a solid sulfide,
• wherein the coating layer comprises a diamond-like carbon,
• wherein the coating layer comprises hydrogen atoms, and
• wherein an amount of the hydrogen atoms is in the range of about 1 atomic percent to about 50 atomic percent, based on a total content of the coating layer.