NEGATIVE ELECTRODE MATERIAL FOR LITHIUM ION SECONDARY BATTERIES, COMPOSITE NEGATIVE ELECTRODE MATERIAL FOR LITHIUM ION SECONDARY BATTERIES, RESIN COMPOSITION FOR NEGATIVE ELECTRODES OF LITHIUM ION SECONDARY BATTERIES, NEGATIVE ELECTRODE FOR LITHIUM ION SECONDARY BATTERIES, AND LITHIUM ION SECONDARY BATTERY

The present invention provides a negative electrode material for a lithium ion secondary battery, a composite negative electrode material for a lithium ion secondary battery, a resin composition for a lithium ion secondary battery negative electrode, and a negative electrode for a lithium ion secondary electrode, which are able to ensure high charge/discharge capacity, and excellent initial charge-discharge characteristics and capacity retention. The surfaces of core particles of silicon of 5 nm or more and 100 nm or less in average particle size are coated with a coating layer to use a negative electrode material containing substantially no silicon oxide in the coating layer, or a composite negative electrode material for a lithium ion secondary battery, which includes the negative electrode material and a matrix material, further with the use of a polyimide resin or a precursor thereof as a bonding resin, thereby making it possible to achieve high charge/discharge capacity and excellent capacity retention, as well as high initial efficiency.