The crystal and magnetic structure and properties of the Na2CoP2O7 Na+-ion battery cathode material have been characterized by magnetic susceptibility, specific heat, and variable-temperature neutron powder diffraction measurements. Na2CoP2O7 crystallizes in the orthorhombic space group Pna2(1) with a = 15.4061(3) angstrom, b = 10.28854(9) angstrom, and c = 7.70316(15) angstrom, having a layered structure with slabs of [CoP2O7](infinity) separated by Na cations. The magnetic property measurements and neutron diffraction data analysis reveal that the material undergoes long-range ordering to a noncollinear antiferromagnetic G-type structure below T-N approximate to 1 6.5 K. The magnetic structure is rationalized as a result of supersuperexchange between Co2+ atoms linked by phosphate groups.