Over　past　decades,　with　the　rapid　development　of　society,　the　growth　of　fossil　fuels　depletion　is　huge.　As　a　result,　the　human　has　to　face　the　emerging　energy　crisis,　which　is　regarded　as　the　bottleneck　to　society　progress.　Meanwhile,　the　use　of　fossil　fuels　has　also　caused　serious　environmental　pollution,　which　in　turn　threatens　ecological　security.　Therefore,　it　is　of　great　significance　to　develop　renewable　and　clean　energy.　Some　natural　power,　such　as　wind　and　water,　have　the　favorable　advantages　of　cleanliness　and　cheap.　However,　the　further　utilization　of　these　powers　is　seriously　hindered　by　their　inherent　characters,　including　intermittence　shortage　and　difficultly　carrying.　At　present,　utilizing　rechargeable　batteries　is　considered　as　an　effective　strategy　to　deal　with　the　above　problems　and　has　become　a　hot　spot　in　scientific　research　and　practical　application.　In　recent　years,　the　fast-growing　technologies　and　new-energy　vehicles　market　are　driving　iterations　of　developing　green,　cheap　and　high　energy　density　energy　system.　In　the　field　of　energy　storage,　lithium-ion　battery　(LIB)　and　sodium　ion　battery　(SIB)　are　developing　rapidly.　In　order　to　meet　the　large-scale　application　of　the　system,　their　energy　and　power　density　need　to　be　further　improved.　As　an　important　part　of　the　battery,　the　anode　material　is　the　main　supplier　of　battery　capacity,　while　the　commercial　graphite　anode　material　has　low　theoretical　capacity　(372　mAh·g-1),　therefore,　it　is　urgent　to　develop　new　anode　materials　with　high　specific　capacity.　In　the　past　few　decades,　transition　metal　sulfides　based　on　conversion　or　alloying　reactions　have　become　potential　anode　materials　due　to　their　excellent　electrochemical　properties.　Metal　sulfides　(FeS,　ZnS,　MoS2,　SnS2,　VS4,　SnS,　Ni3S4,　NiS,　CuS),　the　promising　anode　materials　for　LIBs　and　SIBs,　deliver　the　high　theoretical　capacity,　fast　conversion　reaction　induced　by　the　weak　metal-sulfide　bonds　and　the　safe　working　potential.　Among　them,　cobalt　based　metal　sulfides　(such　as　CoS,　CoS2,　Co3S4　and　Co9S8)　are　favored　by　researchers　for　their　high　theoretical　capacity　(545~870　mAh·g-1).　For　example,　CoS　with　good　conductivity　and　the　theoretical　capacity　of　589　mAh·g-1　has　aroused　tremendous　interest.　However,　the　severe　structure　changes　of　CoS　anode　during　Na　ion　insertion/extraction　process　resulted　in　the　pulverization　of　CoS　anode,　delivering　inferior　electrochemical　performances　accompanied　by　the　unsatisfied　cyclability　and　high-rate　charge-discharge　ability.　Cobalt　disulfide　(CoS2)　as　an　ideal　model　compound　for　both　lithium　and　sodium　storages,　could　provide　a　large　theoretical　capacity　(870　mAh·g-1　for　both　LIBs　and　SIBs)　and　high　conductivity.　Nevertheless,　CoS2-based　anodes　just　like　other　transition　metal　sulfides　suffered　from　serious　drawbacks　such　as　(i)　severe　volume　variation　upon　repeated　(de)lithiation　or　(de)sodiation,　resulting　in　electrode　pulverization　and　thus　poor　cycling　stability,　and　(ii)　rapid　specific　capacity　fading　due　to　polysulfide　dissolution　in　the　electrolyte.　Co9S8,　one　of　transition　metal　sulfides,　has　been　regarded　as　a　promising　candidate　for　next-generation　LIBs　because　of　its　high　theoretical　capacity　(545　mAh·g-1)　with　conversion　mechanism,　as　well　as　widespread　availability　and　low　cost,　the　cubic　Co9S8　composed　of　CoS6　octahedra　and　CoS4　tetrahedra　showed　the　best　thermodynamic　stability.　However,　the　large　volume　change　of　Co9S8　during　(de)sodiation　caused　inferior　electrochemical　performance　and　especially　poor　cycle　stability.　Much　effort　has　been　done　to　address　these　challenges　by　preparing　nano　Co9S8　or　Co9S8@carbon　materials.　Numerous　studies　showed　that　the　synthetic　method　of　anode　materials　was　crucial　for　good　electrochemical　performance.　For　instance,　the　powder　prepared　by　hydrothermal　method　had　the　advantages　of　complete　grain　development,　small　particle　size,　uniform　distribution,　light　particle　agglomeration,　cheap　raw　materials　and　easy　to　obtain　appropriate　stoichio-meters　and　crystal　forms.　Multifarious　nanostructures　could　be　obtained　by　the　control　of　reaction　conditions,　such　as　concentration,　pH,　pressure,　temperature,　duration　time,　etc.　The　hydrothermal　and　solvothermal　technique　were　both　the　simple　and　universal　synthesis　approaches　using　solvents　(aqueous　and　nonaqueous,　respectively)　at　low　temperatures　and　high　pressures　for　fabricating　nano-materials.　The　chemical　reactions　took　place　in　an　autoclave　and　the　processes　were　accompanied　with　three　stages:　formation　of　the　supersaturated　solution,　nucleation　and　crystal　growth.　CNTs　and　CNFs　were　the　most　widespread　oriented　templates　for　the　design　and　fabrication　of　nanostructured　materials.　Usually,　core-shell　structure　could　be　directly　obtained　by　growing　other　materials　on　the　surface　of　template,　while　after　the　template　was　removed　in　the　following　process,　the　hollow　structure　could　be　obtained.　The　electrospinning　technique　was　a　versatile　top-down　method　for　manufacturing　continuous　fibers　(from　the　nanometer　to　micrometer　scale)　by　electrostatic　forces.　The　general　electrospinning　equipment　mainly　contained　three　parts:　(i)　a　spinneret;　(ii)　a　high　voltage　power　supplier;　and　(iii)　a　grounded　conductive　collecting　substrate　(often　a　metal　screen　or　rotating　mandrel).　To　date,　the　precursor　solution　was　primarily　polymer　containing.　There　were　mainly　two　types　of　polymers　used　in　electrospinning.　One　type　was　water-soluble　polymers,　another　type　was　non-water-soluble　polymers.　This　paper　systematically　summarized　the　types　of　cobalt-based　metal　sulfides　(such　as　CoS,　CoS2,　Co3S4　and　Co9S8)　in　lithium/sodium　ion　batteries　and　the　synthesis　method　of　composite　materials,　starting　from　the　materials　commonly　used　for　transition　metal　oxide/sulfide/selenide　and　carbon　composites　for　lithium/sodium　ion　battery　anode　materials　and　looking　forward　to　the　challenges　faced　by　carbon-loaded　anode　materials.　©　Editorial　Office　of　Chinese　Journal　of　Rare　Metals.　All　right　reserved.