▎ 摘　　要

NOVELTY - Nanoparticles comprise at least one component A comprising metals, semimetals, metal compounds or semimetal compounds and at least one coating of graphene. USE - The nanoparticles are useful in electrochemical cells and in supercapacitors for storing and/or releasing lithium ions (all claimed). ADVANTAGE - The nanoparticles: utilize graphene which exhibits good electrical conductivity and high structural flexibility hence withstands the change in volume which occurs during a charge/discharge cycle; and can be used as anode-active materials in lithium ion batteries which have high capacity and remain stable even over a large number of charge/discharge cycles. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) producing nanoparticles, comprising providing a suspension comprising a suspension medium and nanoparticles (containing component A) with positive surface charge, adding graphene oxide particles to the suspension, where the graphene oxide particles accumulate on the nanoparticles, and converting the graphene oxide particles accumulated on the nanoparticles to graphene; and (2) storing and/or releasing lithium ions in electrochemical cells and in supercapacitors by providing nanoparticles as material which stores and/or releases lithium ions in the electrochemical cells and in supercapacitors.