NOVELTY - Preparing stannic oxide/carbon nano hollow ball, comprises: mixing ethanol, aqueous ammonia and water, adding tetraethyl orthosilicate, and mixing; centrifuging the obtained solution, drying the resulting precipitate to obtain dried silicon dioxide nanoparticles; dispersing silicon dioxide nanoparticles in water and ethanol solution mixture, adding urea, and sodium stannate, and stirring; centrifuging the solution, drying the resulting precipitate to obtain hollow stannic oxide nanoparticles; adding aqueous solution of polyacrylic acid and ammonia into above solution, and dispersing.    USE - The stannic oxide/carbon nano hollow ball is useful in a lithium ion battery (claimed).    ADVANTAGE - The preparation method achieves the purpose of integrating the regulating effects of the nanoscale dispersion of nanoparticles to the volume expansion of SnO2, the absorbing effects of the hollow structure to the internal stress generated by volume changes and the restricting and buffering effects of the carbon wrapping layer to stannic oxide particles. and when the hollow stannic oxide/carbon nano hollow ball is applied to the lithium ion battery, The lithium ion battery can have a larger volume, better cycling stability and longer service life upon use of the stannic oxide/carbon nano hollow ball.    DETAILED DESCRIPTION - Preparing stannic oxide/carbon nano hollow ball, comprises: (i) adding 60-80 ml ethanol, 3-4 ml aqueous ammonia and 1-1.3 ml water into 100 ml flask, mixing evenly, then slowly dropwise adding 2-3 ml tetraethyl orthosilicate, and 20 degrees C thermostatically mixing for 6-8 hours; (ii) centrifuging the obtained solution at 7000 revolutions per minute for 8-10 minutes, and then washing with deionized water and ethanol many times alternately, and drying the resulting precipitate in an oven at 50-80 degrees C for 8-10 hours, to obtain dried silicon dioxide nanoparticles; (iii) dispersing 1-1.5 silicon dioxide nanoparticles in 6-7 ml water and ethanol solution mixture, where the volume ratio of water and ethanol is 1:1, then, respectively adding 0.2-0.3 ml 0.2 M urea, and 0.4-0.5 ml 0.08 M sodium stannate into the reaction solution, and magneticcally stirring for 0.5-1 hour; (iv) transferring the obtained solution into 15 ml hydrothermal reaction kettle, placing the oven and reacting at 170 degrees C for 1-2 hours, naturally cooling to room temperature, centrifuging at 7000 revolutions per minute for 8-10 minutes, and then washing with deionized water and ethanol many times alternately, drying the resulting precipitate in an oven at 50-80 degrees C for 8-10 hours to obtain hollow stannic oxide nanoparticles; (v) adding 4-6 mg stannic oxide nanoparticles and 8-12 ml deionized water into 100 ml flask, and ultrasonically dispersing for 10-20 minutes; (vi) adding 60-100 mu l 0.2 g/ml aqueous solution of polyacrylic acid and 90-150 mu l 2 mol/l ammonia into above solution, and ultrasonically dispersing for 10-30 minutes; (vii) under magnetic stirring condition, slowly dropwise adding 90-120 ml isopropanol into solution of step (vi), centrifuging at 7000 revolutions per minute for 5-8 minutes, and drying the resulting precipitate in the oven at 50-80 degrees C for 12-20 hours; and (viii) calcining the obtained solid in a tubular furnace at 400-500 degrees C for 4-5 hours. An INDEPENDENT CLAIM is also included for the stannic oxide/carbon nano hollow ball, prepared as mentioned above.