Abstract: A headset jack includes a side wall, a bottom part, a clamping component on the side wall, a first detection end at the bottom part, a second detection end on the side wall or at the bottom part, and a membrane switch electrically connected to the second detection end. The clamping component is configured to clamp a headset plug when the headset plug is inserted into the headset jack. When the headset plug is not inserted in position, the membrane switch is electrically isolated from the first detection end. The membrane switch is configured to generate elastic deformation under a pressure of the headset plug when the headset plug is inserted in position and be electrically connected to the first detection end.

Abstract: Cathode materials and cathodes for sodium and sodium-ion cells and batteries include sodium, lithium and transition metal oxide cathode materials. An example cathode is the composition NaxLiyNizMnuMvOw, with M being one or more metal cation, x+y?0.9, (x+y)/(z+u+v)>1, (z+u+v)>1, 0?z?0.9, 0?u?0.9, 0?v?0.9, x+y+z+u+v is less than w, and the value of w depends on the proportions and average oxidation states of the metallic elements. The combined positive charge of the metallic elements is balanced by the number of oxygen anions, w. W is less than or equal to 2, i.e., NaxLiyNizMnuMvO2?a, and desirably equal to or slightly less than 2. M is one or more metal cations selected preferably from one or more divalent, trivalent, tetravalent, pentavalent or hexavalent cations, such as Mg2+, Cu2+, Co3+, B3+, Fe3+, Al3+, Ti4+, Zr4+, V5+, and Cr6+ etc. Synthesis methods are provided.