Abstract: Provided are an insulation patch, a battery cell, a battery, and a device. An electrode assembly is coated with the insulation patch, and a side edge of the insulation patch has a hot-melt region and a non-hot-melt region. The hot-melt region is configured to hot melt with a lower plastic, and the non-hot-melt region is lower than the hot-melt region. After the electrode assembly coated with the insulation patch is mounted to a shell, and the hot-melt region of the insulation patch is hot melted to the lower plastic of a top cover assembly, when a top cover member and the shell are welded together by using a laser, the non-hot-melt region of the insulation patch is lower than the hot-melt region, preventing the non-hot-melt region of the insulation patch from interfering with a welding position between the top cover member and the shell.

Abstract: The present disclosure relates to a hydrophobically modified nanocellulose crystal and a method for hydrophobic grafting modification of nanocellulose crystals, comprising the steps: mixing the nanocellulose crystals with a saturated alkane, and stirring the resultant at room temperature or under a heating condition; while stirring, adding in sequence a polymethylhydrosiloxane containing a silicon-hydrogen bond and a catalyst; continuously stirring to complete the dehydrogenation reaction, then obtaining a mixed solution; and filtering the mixed solution by a polyvinylidene fluoride membrane, then drying it to complete the hydrophobic modification. A —Si—O—C-chemical bonding is formed between the polymethylhydrosiloxane and the nanocellulose crystal in the method, enabling improvement of the hydrophobicity and water resistance of the nanocellulose crystal.