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[Display omitted] Binders play a key role in maintaining the integrity of high-capacity silicon anodes, which otherwise experience serious capacity decay during cycling caused by huge volume variation of the silicon. With an aim to developing a highly efficient polymeric binder to mitigate this capacity decay, we present a novel binder synthesized from polyacrylic acid (PAA) and polymerized β-cyclodextrin (β-CDp) for Si anodes for the lithium-ion batteries. This PAA-β-CDp binder has a 3D network structure, which provides strong adhesion between the active material and the current collector. PAA-β-CDp binder makes silicon anode achieve a specific capacity of 2326.4 mAhg−1 at the current density of 0.2 A g−1 with a capacity retention of 64.6% after 100 cycles. The experimental results show that the PAA-β-CDp binder can effectively mitigate the huge volume change and improve the capacity and cycling performance of Si anodes. [ABSTRACT FROM AUTHOR]

The doping of Co heteroatom in the CuS lattice can optimize the electronic structure of CuS, provide more active sites for the adsorption of lithium ions and form more suitable diffusion paths for rapid transport of Li-ion in Cu 2 S 2 layers, thereby resulting in enhanced cycling performance. [Display omitted] • N -type Co doped CuS 1-x with abundant S vacancies in its structure is firstly used as anode material in lithium-ion batteries. • Cobalt doping simultaneously improves Li ion migration and electron transfer kinetics. • A highly conductive and active sites adjacet to the Co atoms are conducive to more rapid electron transfer and energy conversion. • Co-doped CuS 1-x shows impressive rate capability and long cycling stability as the anode material of lithium-ion batteries. Slow Li ion diffusion kinetics and disordered migration of electrons are two most crucial obstacles to be resolved in electrode material design for higher rate capability of Li-ion batteries. Herein, the Co-doped CuS 1- x with abundant high active S vacancies is proposed to accelerate the electronic and ionic diffusion during the energy conversion process, because contraction of Co-S bond can cause the expansion of atomic layer spacing, thus promoting the Li ion diffusion and directional electron migration parallel to the Cu 2 S 2 plane, and also induce the increasing of active sites to improve the Li+ adsorption and electrocatalytic conversion kinetics. Especially, the electrocatalytic studies and plane charge density difference simulations demonstrate that electron transfer near the Co site is more frequent, which is conducive to more rapid energy conversion and storage. Those S vacancies formed by Co-S contraction in CuS 1- x structure obviously increase Li ion adsorption energy in Co-doped CuS 1- x to 2.21 eV, higher than the 2.1 eV for CuS 1- x and 1.88 eV for CuS. Taking these advantages, the Co-doped CuS 1- x as anode of Li-ion batterie shows an impressive rate capability of 1309 mAh·g−1 at 1A g−1, and long cycling stability (retaining 1064 mAh·g−1 capacity after 500 cycles). This work provides new opportunities for the design of high-performance electrode material for rechargeable metal-ion batteries. [ABSTRACT FROM AUTHOR]