The invention belongs to the technical field of lithium ion batteries, and particularly relates to a lithium ion battery. The battery includes a positive plate, a negative plate, isolating films arranged between the positive and negative plates at intervals, and electrolyte. A negative electrode active material includes the following components: 98.1-99.8 percent of a negative electrode active substance, 0-1 percent of a negative electrode conductive agent, 0.1-1 percent of a negative electrode binder and 0.1-1 percent of a negative electrode stabilizer. The viscosity of the stabilizer is 2000mPa.S to 15000mPa.S. The negative electrode conductive agent is at least one of carbon fiber, carbon nanotubes, carbon nanorods and grapheme, or is a mixture of carbon black and at least one of carbon fiber, carbon nanotubes, carbon nanorods, phosphorus graphite and grapheme. In comparison with the prior art, the lithium ion battery has the advantages that the battery energy density is improved and the high rate charging / discharging characteristics are improved on the premise of ensuring that the diaphragm is not stripped.