Cu2S　hollow　spheres　composed　of　nanoparticles　are　synthesized　via　a　template-free　hydrothermal　process　in　the　absence　of　additive.　The　obtained　Cu2S　hollow　spheres　not　only　provide　a　large　surface　for　contacting　between　electrode　and　the　electrolyte,　but　also　keep　sufficient　space　for　the　volume　variation　during　the　sodiation/desodiation　process.　Consequently,　as　an　anode　for　sodium　ion　battery,　the　Cu2S　hollow　spheres　deliver　a　large　capacity　of　369　mA　h　g−1　after　100　cycles　at　0.2　A　g−1　and　demonstrated　superior　rate　performance　(331.7　mA　h　g−1　at　0.5　A　g−1,　319　mA　h　g−1　at　4　A　g−1)　and　long-term　cycling　stability　(343　mA　h　g−1　at　2　A　g−1　after　1000　cycles).　©　2020　Elsevier　B.V.