Cellulose is the most earth-abundant natural polymer resource, which with combined eco-friendly and extraordinary sustainable properties such as renewability, biodegradability, low cost and excellent biocompatibility has been widely used by humans for thousands of years. In the past few years, many novel cellulosic materials and their unique applications have been developed including the recent research focus on energy harvesting. The high crystallization and plentiful polar hydroxyl groups endow cellulose with a large number of dipoles and strong electron donating capacity, resulting in a promising potential of piezoelectric and triboelectric effects. However, there is no review about cellulose-based nanogenerators until now. In this paper, the most recent developments of designing, modification, processing and integration of cellulose-based piezoelectric nanogenerators (PENGs), triboelectric nanogenerators (TENGs) and hybrid piezo/triboelectric nanogenerators (PTENGs) for energy harvesting and other applications are reviewed in detail. For cellulose-based PENGs, representative basic piezoelectric cellulose and recent research on PENG devices are discussed. For cellulose-based TENGs, several effective strategies including rough modification of contact surface, addition of electronic functional fillers and chemical modification for improving the output performance are further summarized. Meanwhile, the latest cellulose-based hybrid PTENG is also introduced from the fundamental design to the investigations on enhanced strategies. The opportunities and challenges of these cellulose-based nanogenerator devices are put forward in the final part, which could enable this up-to-date and state-of-the-art review to be an effective guidance for the future research on cellulose-based nanogenerators in energy harvesting.

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基于纤维素的压电和摩擦电纳米发电机在能量收集方面的最新进展：综述

纤维素是地球上最丰富的天然聚合物资源，具有生态友好和非凡的可持续特性，例如可再生性，生物降解性，低成本和出色的生物相容性，已被人类广泛使用了数千年。在过去的几年中，已经开发出许多新颖的纤维素材料及其独特的应用，包括最近对能量收集的研究。高结晶度和丰富的极性羟基使纤维素具有大量的偶极子和强大的供电子能力，从而产生了压电和摩擦电效应的潜力。但是，到目前为止，关于纤维素基纳米发电机尚无任何评论。本文介绍了设计，修改，详细回顾了纤维素基压电纳米发电机（PENG），摩擦电纳米发电机（TENG）和混合压电/摩擦电纳米发电机（PTENG）用于能量收集和其他应用的处理和集成。对于基于纤维素的PENG，讨论了代表性的基本压电纤维素和有关PENG器件的最新研究。对于基于纤维素的TENG，进一步总结了几种有效的策略，包括对接触表面进行粗糙的改性，添加电子功能性填料以及进行化学改性以改善输出性能。同时，最新的纤维素基杂化PTENG也从基础设计引入到对增强策略的研究中。