Hard carbons derived from pine nut shells as anode materials for Na-ion batteries
Guo Hao1, Sun Kai1, †, Lu Yaxiang2, 3, ‡, Wang Hongliang1, Ma Xiaobai1, Li Zhengyao1, Hu Yong-Sheng2, 3, Chen Dongfeng1, §
       

(a)Voltage profiles and (b) reduction capacities of PNSHC-T electrodes at 0.1-C rate in the second cycle.